Making a tin-can hit-man.

[Admiral Squish]

So, I came up with a rather interesting idea for an aquatic campaign starting soon. A warforged S.E.A.L. Trouble is, I'm struggling what exactly should be included to make the effect. The DM is real easygoing, but it's starting at level 2, so there's not too much game-breaking just yet. I'm probably going to make some kind of 'aquatic plating' feat to give him a swim speed.

Anyway, I was considering ninja for one half of the gestalt, but I'm not sure how plating interacts with armor and such, and I'd need to tweak the abilities to work with the aquatic world. But I don't know what to put on the other side. Ranger? Wilderness rogue, perhaps?

[Ernir]

How attached are you to the Ninja class? Because Rogue does Ninja better than Ninja does. And so does the Swordsage.

[Admiral Squish]

Would probably solve a lot of problems to swap out ninja, actually. Armor issues and such. But that still leaves me with the question of what do I do with the other side?

[Vaynor]

Maybe Ranger -> Horizon Walker for the other side? It would let him work well in many environments, more adaptable and all that jazz. I don't know much about that though. But as for the plating, how about the warforged being partly hollow, and he is able to change the amount of water inside him to sink/float. Then I'd assume built in fins on the feet and webbed hands, along with an aqua-dynamic top so he'd be able to swim more easily. Maybe even alter the armblade to be on his head (as if a narwhal). Maybe even give him a linked, prehensile tail (with a fin at the end of it) to allow for more control in the water. Not sure what level you'd be starting at (I'm blind), but I'm sure there's a way to magically fashion a jet to put on his back for extra speed (and probably the ability to run/sprint/charge). Hope this helps.

[Admiral Squish]

I was thinking of the whole internal ballast tanks idea. Some retracting fin-like structures and maybe little feet-propellers. Not sure exactly how to flavor it, though. The main point is the swim speed. Some light armor is nice, too.

The other main point is stealth. This is the guy who can take down your entire base before you even know he's there. The only mark of his presence is where the patrols keep disappearing. As bad-a$$ as all those mods sound, not many are conducive to sneakin'.

[Vaynor]

Indeed, I can see being hollow and made of metal not helping much with sneakiness. Perhaps the inside is filled with a sponge of some sort, to dull any noises?

Edit: You also mentioned the fins being retractable, that would definitely help with stealth as well (large finned feat don't exactly work well with Move Silently). Would he need to be stealthy above land as well, or just in the water?

[Boci]

Indeed, I can see being hollow and made of metal not helping much with sneakiness. Perhaps the inside is filled with a sponge of some sort, to dull any noises?

Unarmoured body? (Its from races of eberron I think)

[Icewraith]

At higher levels, strap a decanter of endless water to your back. Only problem then is braking.

[Admiral Squish]

So, I'm looking at, what? Wilderness rogue//?

I'm debating assasin. It looks good to me, but is it a trap? This will be my first really sneaky-focused character, so forgive me if it's a stupid question.

I still need something to put on the other side. One level of ranger for track and favored enemy and whatnot, most likely, and then what? Swashbuckler might be another nice dip, but I still need to fill out 16 levels.

[mabriss lethe]

a level of warlock and the 'swimming the Styx' invocation from complete mage will grant you a swim speed. plus the eldritch blast means you're always armed and ready to nail a ranged sneak attack.

[Admiral Squish]

...Actually, pretty awesome. Easily flavored as a built-in 'magic gun' or something. Convenient, irremovable... One shot only, though, but that's hardly a detriment at 2nd level.

Right now we're looking at Wilderness rogue 2//Ranger1/Warlock1 to start, progressing to wilderness rogue 20//ranger 1/warlock 1/Swashbuckler 3/assassin 10/... then something else for five levels. At this point I'll have had plenty of time to think of something anyway.

[Keld Denar]

You could always pick up a couple more levels of Warlock and make use of Eldritch Glaive (Dragon Magic) as your main weapon. Tack some Power Attack and some Sneak Attack on that bad boy, not to mention IMPROPTU DEATH ATTACK TO THE FACE!

Also, Flee the Scene is great for an assassin type. I mean, just look at the freakin name! FLEE THE SCENE! Walk Unseen is also very convenient for an assassin type.

[Admiral Squish]

I might try to talk my DM into changing assassin spellcasting into invocations, anywho. I hate vancian magic, anyways.

For a main weapon, I was thinking more along the lines of a retractable punching dagger in my arm. Possibly with a poison reserve.

[mabriss lethe]

swapping out swordsage for assassin would give you more options if you're willing and able to use TOB. The casting/death attacks really don't compare to the assassin-like shenanigans that a sneaky swordsage can pull off. Invisibility, short range teleport, sneak attack. Miss chance, ability damage....and that's just shadow hand.

Also, there really isn't any reason to take rogue all the way up to 20. take it to 19 and then pick up a level of...anything else somewhere along the way. There isn't any capstone ability for 20th level rogues.

If you choose to take a few more levels of warlock, you can start taking the feats to make him a shadow-lock. (They're in Drow of the Underdark. requires the use of Darkness as a spell like ability, and invocations qualify ,you can blow darkness SLAs to get hide in plain sight and a few other goodies.)

[Seffbasilisk]

Consider the armor enhancement from Stormwrack. Get a keel for 50gp to give you a +2 to swim.

[Lycanthromancer]

Isn't there a really cheap way to give armor the buoyant property? I think it's like +500 gp or something. Or was that an armor crystal? I forget.

Anyway, swordsage//martial rogue, swordage//psychic warrior, or swordsage//fighter, and take lots of Martial Study and Martial Stance feats. The first one gets extra skills, the second gets psionic powers, and the third one gets BAB. The first and second are the most flexible, the second is the most powerful, and the third...well...gives you BAB.

[Admiral Squish]

I have nothing against TOB, myself, but I haven't had time to really read it through, so I'm going to pass on all the SS suggestions.

[Lycanthromancer]

I have nothing against TOB, myself, but I haven't had time to really read it through, so I'm going to pass on all the SS suggestions.Too bad, 'cuz it'd be a riot to play, and it'd do just what you want it to do, really.

How about wildshape ranger/MoMF/warshaper//martial rogue?

[Soronhen]

If you have access to Heroes of Battle, the Dread Commando fits the flavor you seem to be going for, and will also help relieve any armor check penalties you might be worried about.