The god, Tharizdun

Alright, I'm playing 4th edition but since this is D&D lore it shouldn't really matter all that much. I've been DMing a campaign for 2 years, it's a huge campaign that we've all committed to, and I've had a general idea of the BBEG.

Just recently I leafed through the DMG for the first time in a while and came across Tharizdun.

Tharizdun
Thriszdun is the chaotic evil god who created the Abyss. He is not mentioned in the Player's Handbook or named in the Monster Manual, because the fact of his existence is not widely known. A few scattered cults of demented followers revere him, calling him the Chained God or the Elder Elemental Eye. Tharizdun doesn't speak to his followers, so his commands are unknown, but his cults teach their members to:
- Channel power to the Chained God, so he can break his chains.
- Retrieve lost relics and shrings to the Chained God.
- Pursue the obliteration of the world, in anticipation of the Chained God's liberation.

Now, if you were me this would basically be the BBEG you had roughly designed a while back. He is perfect.

Only thing is, that's it (understandably). That said, I was wondering if he exists in other editions and if so, if anyone can tell me more about him (or her)?

edit: Read the wiki article on him btw which does tell me more but still leaves out substantial chunks. I've also only found one picture of him which seemed to be a floating black mass with an eye and dark tendrils extending from it.

Try to find a copy of 2nd Ed dungeon module WG4 - Forgotten Temple of Tharizdun. It's got a bit of info and details on how a temple is laid out.

- Even other evil gods want to see him stay chained. Lolth in particular has a problem with Elder Elemental Eye cults springing up in Drow settlements.
- His followers aren't actually going to get a reward if he's freed.
- The Elder Elemental Eye is actually not closely associated with him, and its cults often pose as benign worshippers of elemental forces. The higher-ups know better, though.
- The cults of the different aspects of the Elder Elemental Eye are lead by four elemental princes, Imix of Fire, Yan-C-Bin of Air, Olhydra of Water, and Ogremoch of Earth. Though it would seem that they should be working towards the same goal, they appear to have forgotten it, and are as likely to turn on each other as their other enemies.
- Each cult of elemental evil attracts not only mortal followers, but also powerful entities from their respective elemen, such as Salamanders for fire and Krakens for water.
- Source: Monster Manual IV, 3.5, Drow of the Underdark, 3.5.

Yeah, this is just sounding better with each post, the perfect baddie to end a several year long campaign with.

I am a bit dissapointed he's not the Elemental Eye though, I liked the imagery of that. Giant, one eyed mass of tentacled darkness.

edit: That isn't to say that my players are D&D buffs who know their lore, I can adapt as needed.

I always pictured Tharizdun as one of the embodiments of Cthulhu-like Elder Evils or the Far Realms. A figure bad enough to be entirely omitted from common knowledge, bad enough that any mention of efforts to revive him sends a panicked response from those who know. Like many such figures, he would seem to work best as a threat around the corner, rather than an active player.

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The Return to the Temple of Elemental Evil uses Tharizdun in this way, and might have some great inspiration for you.

No, he is the Elemental Eye, just no one knows he is except the people that locked him away in the first place and the very highest-ranking/smartest priests of him or one of the aspects.

Tharizdun is a bit of an ink blot test. You see in it (for petty concepts such as gender don't really apply) what you will.

For the record, Gygax himself answered a host of questions about the dread deity at: http://ulmo.mux.net/greyhawk/tharizdun.html. Good stuff there from the original creator.

Temple of Tharizdun is a 1st edition module, by the way, though they're close enough that it's virtually pointless to distinguish. It's a great resource for the type of weird and strange atmosphere surrounding the type of place Tharizdun is associated with. Also good is G1 Hill Giant's Steading. There's some stuff in the basement there that's important. G3 also has a bit of good info, though it's largely inferred. D1,2,and 3 also have snippets of good stuff on some of his cultists.

Tharizdun is, largely, a Lovecraftian type entity, or at least an homage to one. It is what you make of it.

Oh, awesome then.

I love the secretive aspect of him and it's one of the greatest reasons I chose him. Below I've detailed the campaign, most of this is a mystery to my players but there have been subtle hints. I've adjusted it to include the new information about Tharizdun.

And trust me when I say, I didn't change much at all. The gems existed in my campaign (although, originally as a different form but adjusted to fit the lore), the concept of Tharizdun already existed (I had orignally called him the World Eater which is also one of his actual aliases) and my cult was conveniently named very close to one of his.

They don't use his symbol though.

Thanks for the info so far!

Campaign:

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Around 800 years ago a great war broke out between a major Tiefling and Dragonborn kingdom. This was a brutal war, the Dragonborn prevailed through skill while the Tieflings developed advanced weaponary (including spells).

Things went on for about 30 years, intense warfare, until the Dragonborn were able to recruit allies after gaining intel that the Tiefling kingdom was ready to release an incredibly devastating weapon which would proove harmful to not only them but whole other nations.

The new allies stormed and conquered the Tiefling home and in a last ditch attempt the Tieflings unleashed the weapon on themselves.

This weapon, unwittingly, was (now that I know) Tharizdun. The Tieflings had enough intel to know that gathering the 333 crystals released a tremendous power but they had no idea what.

Tharizdun broke into the mortal world and existed for all of 30 seconds.

In the first 10 seconds he wipes the Tiefling's city off the map, killing everyone inside.

After 20 seconds he had devoured half the continent and burrowed down into the crust, hungry to consume the world from the inside out.

After 30 seconds he consumed the core of the world and the planet began to shatter.

Gods, both good and evil, intervened the moment Tharizdun consumed the core and turned it around on him, trapping him inside and making the core the 334th crystal. They then took Tharizdun's chains and bound the world together with them to prevent it's destruction (in my campaign, the chains are made of pure, arcane energy) and used the 333 gems to create crystals on each planet fragment which would draw natural arcane energy to power the gems.

Many nations had to sacrifice this energy up front though and so there were mass ritual sacrifices of those with strong arcane powers. This prevented communication between nations for a long time (most which had no clue what happened) and resulted in a large loss of information as the Tiefling city had been destroyed.

Fearing that Tharizdun would be sought after by foolish mortals yet not trusting even their own followers, the gods put him in orbit as the red moon. Far from the reach of any mortal.

Now, 800 years in the future, a group called the Brotherhood of the Red Moon (now, officially an offshoot of the Scarlet Brotherhood thanks to wiki) is following orders from Tharizdun's avatar, Shothragot who I need to learn more about. They are focusing on collecting the gems under a false promise that this will help reunite the planet back to it's previous form.

Beyond this they know nothing but they're willing to go to extreme lengths for the gems. The party has two (without realising it) which, unless properly contained, exude horrible energy, warping everything around them into chaos.

You your campaign world is a bunch of floating landmasses in the aether? Sounds like a cool place to play :smallcool:

Yep, my players just found this out a short while ago. They live on a continent which believes if it's populace doesn't know about the true state of the world things will be better.

It is the safest continent but due to it's outlook it is far back technologically since it restricts most trade and communication with other continents (airships barely exist at all while they're commonplace everywhere else. This is a necessity for travel obviously).

My players enjoy it so far and I wanted to make sure I started developing the BBEG stuff (and paragon stuff) in detail now that they've gotten this far.

Interesting setting... you may want to look at The Shattered World (and sequel, The Burning Realm) by Michael Reaves for inspiration. It's a very D&D-like world in some ways, which has been broken ages ago - people now use skyships to travel from one piece of land to the next. 'Demons', named chtonians have the power to teleport and are therefore of great use to potent and more or less sane wizards - their leader is, of course, the Demogorgon.

Fun stuff.

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Originally Posted by Sipex

Alright, I'm playing 4th edition but since this is D&D lore it shouldn't really matter all that much. I've been DMing a campaign for 2 years, it's a huge campaign that we've all committed to, and I've had a general idea of the BBEG.

Just recently I leafed through the DMG for the first time in a while and came across Tharizdun.

Tharizdun
Thriszdun is the chaotic evil god who created the Abyss. *snip*

- Channel power to the Chained God, so he can break his chains.
- Retrieve lost relics and shrings to the Chained God.
- Pursue the obliteration of the world, in anticipation of the Chained God's liberation.

Now, if you were me this would basically be the BBEG you had roughly designed a while back. He is perfect.

Only thing is, that's it (understandably). That said, I was wondering if he exists in other editions and if so, if anyone can tell me more about him (or her)?
*snip*

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Hmmm.. so much more material about this god exists than I thought did when I used him as BBEG. He's like a campaign-in-box kit, really.

-He's in Complete Divine (3.5) as the only god who provides the Force domain, which in and of itself is interesting. I decided to set up a campaign where [Force] magic and the makeup of the Planes were closely linked, and where Thardizun was imprisoned by other gods using very powerful force magic. The study of force and the planes was highly integral to the plot, and the villain breakdown is Cult of Thardizun vs. Hextor and Mechanus (the workings of which keep big T imprisoned).

-As far as appearance and fluff, he's whatever you want him to be... I only ever had access to the short blurb about him in CD3.5, but I guess that's what I liked about him: he was open for my own expansion.

-IF you really want him to be as he is in D&D canon, look up Temple of Elemental Evil... CDivine says Thard is listed in a book called "toee" which I assume is that. Other than that, a generic god of slaughter is the starting point for your BBEG.

When I ran a particular 3.0 mega dungeon (that has already been spoilered earlier in this thread) I ended up elaborating on the Big-T worship aspect of the campaign, even going so far as to chat with Gygax himself (through e-mail. What an awesome guy, to just oblige a random DM like that) about the Dark One.

I've lost pretty much all my notes in the decade since then, but I'll go over some things I remember. I forget what info I got from source and what I came with on my own. Most of it was from one source or another. Just for fun, I'll write this all from the perspective of a mad cultist.

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There is the Great Wheel. Infinite in many aspects, but those of us who are enlightened can easily understand the concept of multiple infinities coexisting within the same multiverse. The Abyss itself is said to hold infinite lairs, each of infinite space. And this is but a spoke on the Great Wheel.

But when looked at from a whole, the Great Wheel is but a small pebble in the sea of an Omni-infinity. But what lies in this dark ocean outside of everything that is? It is Nothing. And His name is Tharizdun.

The Chained God, my Master, is Everything that is Not. He is the All-Nothing. And He is far greater than what Is. The Gods we know have carved a multiverse from a small wound in His side, but the one inevitability of creation is that it will one day be unravelled. But fear not, for we should not try to escape the unravelling! Nay, for only when we are unmade will we be returned to the Great Nothing from which we were stolen.

You see, my Master, he is not chained within some limited prison, as many "studied" scholars seem to think. How small minded are they! They think that the Great Wheel is all that is! No, my Lord has been chained without of this fragile shell, locked into the infinite infinities beyond! He is being held away from this existence by greedy hands, who still seek to steal His power, and hide it from Him.

Before creation, the children of the One God rebelled against Him, and against His vision. We do not know what he sought to do with this power - but I can only guess it would have been beyond description! But the jealous child gods stole the power while their Father slept, and made the Great Wheel in his shadow.

Wounded, was the Great God, and he sought to reprimand His children and undo the travesty that they had done. The children couldn't even form a unity between themselves on how to use this power that they had no responisbility for. The mockery they call Pelor - the eldest of my Great Lord's children, created an uneasy alliance between his sibilings, and together they locked the gates to their Piteous Wheel, so their Father could not correct what they had done.

Soon after, these childish gods forgot their Father, and resumed their pathetic squabilling with each other in their tiny toy house.

But, fear not, my dear friends, and followers of the Great Nothing! For every lock has a key. The Theoparts. Holy relics that are but a fraction of the Lord's power that was trapped within this world. When the three of them are reunited, the door to this reality will be revealed, and Tharizdun will finally be able to know the way in, to right what has been wronged. And he will not forget his loyal followers - that aided him even when he was unable to speak to us!

But we see his works, even so. The beautiful gateways that scholars call Spheres of Annihilation - holes in the fabric of the Great Wheel... they are the signs that our Lord is finding his way into the world - that he will be here soon!

Also, some of our more blessed members, have been visited by the Dark One in dreams. He appears as a seven foot tall striking blonde man in black armor. The path to his haven is a solid rainbow of light, and his glorious castle is crafted of pure crystal, resting on a cloud. The only thing he is able to ask about is his key - the theoparts - and he demands that we should bring these relics together!

Another piece of his power was able to form into the being we know as the Elder Elemental Eye - but this powerful being is like a lost child, forgetting it's true place and purpose. Nonetheless, it is our Lord's true avatar within existence, and we should seek to do it homage. Unfortunately, the 333rd layer of the abyss - it's domain - has been sealed off to all beings. I suspect that there is a weak point in the structure of the Great Wheel somewhere on the plane. If only there was some way to gain access!

But do not despair, my friends. We will prevail. There is no stopping it, not even if all the gods were to rise together again could they stop His power. We will be unravelled. And when the Great Tharizdun remakes the world in His Image, according to His Design, we His followers will be given sacred places on high as our eternal reward!

Oh, Great Tharizdun - Entropy to this Accursed Existence - we will usher your way soon, so you may Unravel this unworthy existence that was stolen from your Holy side!

I think what makes these theories most compelling is there is truth to them. Big T is basically an Overdeity that wasn't invited to the party, so he wants to wreck everything and do it his own way. Whether or not he'll "remember" the followers that helped him is another matter entirely, though.

All in all, Tharizdun is a great concept. It worked especially well in my campaign when the PCs started to see some merit in the crazy cultist viewpoint. Anyway, I hope this mad cultist's ramblings were enjoyable at least, if not insightful.

Sorry that ended up being pretty long...

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Originally Posted by meschlum

Interesting setting... you may want to look at The Shattered World (and sequel, The Burning Realm) by Michael Reaves for inspiration. It's a very D&D-like world in some ways, which has been broken ages ago - people now use skyships to travel from one piece of land to the next. 'Demons', named chtonians have the power to teleport and are therefore of great use to potent and more or less sane wizards - their leader is, of course, the Demogorgon.

Fun stuff.

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Incredible setting and great books, but why, oh why, did Reaves never write the third? The story ends in the middle!

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Originally Posted by Achernar

-IF you really want him to be as he is in D&D canon, look up Temple of Elemental Evil... CDivine says Thard is listed in a book called "toee" which I assume is that. Other than that, a generic god of slaughter is the starting point for your BBEG.

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That is the subject of some debate and not a little nerd rage. The cross identification of Tharizdun with the Elemental Evils is contentious and is not generally accepted.

But then again, it's whatever you want it to be, so there.

Personally, I like the idea of them being separate, but the EE being influenced/controlled by T. Wheels within wheels . . .

Well, one of my problems is I have problems making monsters similar to him. I usually make them too ridiculous to be threatening so I needed some sort of place to start.

I like the anphimorphous black shadow blob with an eye and shadow tentacles idea. Simple, creepy, and threatening.

edit: Hm, there's a lot to this. Glad to hear :)

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Originally Posted by Sipex

Well, one of my problems is I have problems making monsters similar to him. I usually make them too ridiculous to be threatening so I needed some sort of place to start.

I like the anphimorphous black shadow blob with an eye and shadow tentacles idea. Simple, creepy, and threatening.

edit: Hm, there's a lot to this. Glad to hear :)

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Read Temple of Tharizdun, especially the part about the Black Cyst in the bottom. Sometimes, the biggest threat from T is existential and not in the form of a monster. Sometimes, it's just the urging for people to be themselves and go after what they want with the lifting of inhibitions.

Remember, nothing is scarier.

As for specific monsters, remember that most monsters aren't going to want to cooperate with that guy. They kind of like existing, so T and cultists would either have to have a front that is more palatable, or flat out lie to potential followers. Abominations of the nastiest sort are possibilities, but generally, any monster that revels in destruction for the sake of destruction, who seeks no dominion, who wants to utterly annihilate everything, are the key there.

Oh yeah, I'm not planning on having monsters be fine with him. My PCs are fairly predictable in a good way so they'll soon start collecting the crystals to prevent my cult from doing so (who has no idea about what is going on).

From there, everything will be trying to prevent this, the remaining crystals are mostly sealed away in veritable death traps guarded by monsters and traps.

For those crystals that aren't sealed away the PCs will still have to do a lot to get them. One particlar planned example is a hermit just outside a distant village finds one. Getting news of this the PCs will go to him and find him in his cottage, injured, with the crystal and babbling "Don't let it in" before dying dramatically.

From there they deal with a Nightwalker who works on converting the whole village into Bodaks to wrestle the crystal from the PCs and take it to the shadowrealm.

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Originally Posted by Achernar

-He's in Complete Divine (3.5) as the only god who provides the Force domain, which in and of itself is interesting. I decided to set up a campaign where [Force] magic and the makeup of the Planes were closely linked, and where Thardizun was imprisoned by other gods using very powerful force magic. The study of force and the planes was highly integral to the plot, and the villain breakdown is Cult of Thardizun vs. Hextor and Mechanus (the workings of which keep big T imprisoned).

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Heh, so THAT'S who Mechanus Bot is designed to fight... :smallamused: Now there's a great image. Riding Mechanus Bot to fight Tharizdun. :smallbiggrin:

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Originally Posted by Sipex

From there they deal with a Nightwalker who works on converting the whole village into Bodaks to wrestle the crystal from the PCs and take it to the shadowrealm.

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Well, that'd certainly be a nice break from playing a children's card game to resolve all of one's problems.

I'm afraid I don't follow. I don't know Yu-gi-oh.

Oh shoot, I realise it.

Shadowfell, SHADOWFELL.

:P

hamlet: Exactly - any cult bent on destroying everything that exists usually has problems attracting anything but the most insane of parishioners. That's why there's hardly any Cults of Tharizdun running around. That's also why the Elder Elemental Eye worked so well - the vast majority of people didn't know they were worshipping The Chained God.

Tharizdun makes for a GREAT end of campaign villain. The stakes don't get much higher than All Of Creation! Plus the final adventure basically writes itself - they've managed to prevent the insane cultist from opening Tharizun's cage, and everything is safe. However, so long as Tharizdun exists, the possibility of his eventual and inevitable escape looms in the distant future. Therefore, there is but one thing to do as Big Damn Heroes: make the one-way trip into the Prison Plane of Tharizdun and kill him, once and for all!

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Originally Posted by Bruendor_Cavescout

Tharizdun makes for a GREAT end of campaign villain. The stakes don't get much higher than All Of Creation! Plus the final adventure basically writes itself - they've managed to prevent the insane cultist from opening Tharizun's cage, and everything is safe. However, so long as Tharizdun exists, the possibility of his eventual and inevitable escape looms in the distant future. Therefore, there is but one thing to do as Big Damn Heroes: make the one-way trip into the Prison Plane of Tharizdun and kill him, once and for all!

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Disagree. Tharizdun is, or should be, unkillable. He is the embodiment of malicious entropy, decay, and mindless destruction. He is not just a god. It took an entire pantheon to simply seal him away. No hero, or group of heroes, no matter their stature, should have the ability to do anything before Tharizdun except to cease to be.

But that's a matter of play style.

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Tharizdun makes for a GREAT end of campaign villain. The stakes don't get much higher than All Of Creation! Plus the final adventure basically writes itself - they've managed to prevent the insane cultist from opening Tharizun's cage, and everything is safe. However, so long as Tharizdun exists, the possibility of his eventual and inevitable escape looms in the distant future. Therefore, there is but one thing to do as Big Damn Heroes: make the one-way trip into the Prison Plane of Tharizdun and kill him, once and for all!

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The heroes, battered and broken, limp across the fields of skin and ichor under the twisting, non-euclidean sky. The great chasm which was the Eye, now scorched with arcane flames, is lifeless. All the non-matter which was the representation of Tharizdun that their interaction with the Prison formed begins to wither and fall away. Only an absolute Void remains. With absolute certainty, the heroes know they are completely alone in the Prison. No deity may reach here. No arcane power flows into here. No time passes, and with no shifts or changes to mark the passage of any time, past, present and future are indistinguishable.

Identity rapidly decomposes the heroes who slew the beast. What was four bodies, four souls, blends into three, then two, then one, then none. There is only the absolute Void within the prison. Only the Void, and the memory, that there once was something, something which existed, which stood out from the Void. Something which came to this place. To fight or destroy something? Impossible. Something which came to this place, it must have been placed here. Chained here. Chained into the Void. The Void is a prison. There is no time. There is no past or future. The thing which is a no-thing which is the Void seeks for a name, seeks to take a name for itself. Tharizdun?

Any name will suffice. Tharizdun. There is no past or future, only now. But from the perspective of the world outside the Void, there will come a time when the dread Tharizdun will rise for the first time from this Prison and rip a great Abyss in the world, a small void connecting to the lesser Void. Will this be a repeat of what previously occurred? Or were they always one and the same? There is no future or past. The Eye looks out into you, and you look out through the Eye.

Sorry. Couldn´t resist. :smallredface:

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Originally Posted by Analysis

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The heroes, battered and broken, limp across the fields of skin and ichor under the twisting, non-euclidean sky. The great chasm which was the Eye, now scorched with arcane flames, is lifeless. All the non-matter which was the representation of Tharizdun that their interaction with the Prison formed begins to wither and fall away. Only an absolute Void remains. With absolute certainty, the heroes know they are completely alone in the Prison. No deity may reach here. No arcane power flows into here. No time passes, and with no shifts or changes to mark the passage of any time, past, present and future are indistinguishable.

Identity rapidly decomposes the heroes who slew the beast. What was four bodies, four souls, blends into three, then two, then one, then none. There is only the absolute Void within the prison. Only the Void, and the memory, that there once was something, something which existed, which stood out from the Void. Something which came to this place. To fight or destroy something? Impossible. Something which came to this place, it must have been placed here. Chained here. Chained into the Void. The Void is a prison. There is no time. There is no past or future. The thing which is a no-thing which is the Void seeks for a name, seeks to take a name for itself. Tharizdun?

Any name will suffice. Tharizdun. There is no past or future, only now. But from the perspective of the world outside the Void, there will come a time when the dread Tharizdun will rise for the first time from this Prison and rip a great Abyss in the world, a small void connecting to the lesser Void. Will this be a repeat of what previously occurred? Or were they always one and the same? There is no future or past. The Eye looks out into you, and you look out through the Eye.

Sorry. Couldn´t resist. :smallredface:

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:wipestear: Beautiful, just beautiful.

If you're interested in more 4E-centric Tharizdun fluff, Demonomicon's introductory section (History of the Abyss) has some good stuff.

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Basically, Tharizdun is the god who finds the shard of pure evil from another reality (sent to our reality by the Obyriths), which makes him insane. The Obyriths wanted Tharizdun to plant the seed of evil in the Astral Sea, but instead he placed it in the Elemental Chaos, creating the Abyss. When the Obyriths emerged into our reality, Tharizdun fought them to a stalemate for control of the newly formed realm, creating the first demons to be his minions.

Eventually, powerful Primordials noticed the swirling vortex of the Abyss and were tempted within by the power of the shard of evil, transforming into Demon Princes by the corrupting power of the Abyss. During their search, the shard was lost into depths which even these mighty beasts feared to enter, and so the Princes established their own kingdoms and set about pursuing their own goals.

Meanwhile, Tharizdun disguised himself as the Elder Elemental Eye and retreated to the Elemental Chaos to rally the Primordials to make war on the Gods of the Astral Sea, sparking the Dawn War. While that conflict raged, Tharizdun sent his chief lieutenant to assault the Abyss and reclaim the shard of evil. Realizing his true goal, the Gods banded together to lock Tharizdun away in a remote layer of the Abyss, forevermore calling him the Chained God. The remnants of Tharizdun's followers were eventually defeated and the war ended.

Demonomicon also has a neat story about the origins of 4E Asmodeus. :smallwink:

I like the idea of Tharizdun along the ideas of the rifts in the OotS comic or the Oblivion War in the Dresden Files books. In OotS no one can know about the rifts because of what they represent, a threat to the very existence of reality. The Oblivion War in the Dresden Files works on this sort of principle and the principle of belief laid out in Deities and Demigods. Essentially, there are a number of demons/Old Gods that exist outside of the nature of existence. Mortal beings, simply by believing or thinking about them, give them a firmer grip on reality. The more people know about an Old God, the more it can manifest itself in reality. This makes for a very hard fight. The only way to keep these ancient beings from power is to eradicate any mention of them in texts and in the thoughts of mortals.

The problem then for these fighters, called the Venators in the Dresden-verse, is that the more of them they have on their side to fight, the stronger their opponent becomes. I like the idea of a campaign based around this principle when it comes to Tharizdun. Tharizdun would be the nameless, shapeless void that exists between places and outside reality. By giving name to this void, it gains intelligence and eventually malice. It is the anti-thesis of existence, as the saying goes, "nature abhors a vacuum." The more people who know about the dark place between things the stronger it becomes.

The goal for a campaign focusing on this problem then is making Tharizdun cease to be. You can't tell the king why you need his weapons for this fight or even pray to your god for help against him because doing so only makes him stronger. Should enough believe in Tharizdun, the thin veil separating what is and what is not will be rent and He will unmake all that is. Beyond that, no one knows. Perhaps He will remake existence as he sees fit is what his followers and believers hope for but the very few scholars who know of Him meditate on the darker truth - why would the Great Unmaking every create once all is destroyed?

TL;DR Tharizdun in my campaign would gain strength by people simply believing he exists. That is enough to eventually destroy his prison and allow him to unmake the multiverse.

Except if you're worshipping a god that doesn't already know about Tharizdun, you're probably already SoL...