Human Wu-jen/Monk Gestalt, lvl 20.

[visigani]

How could that Wu-jen/Monk solo a Great Wyrm Red Dragon?

[Gavinfoxx]

How could that Wu-jen/Monk solo a Great Wyrm Red Dragon?

What are the Wyrm's spells and feats? Why no prestige classes? What alternative class features are being used, or are available? Is the Monk a Wild Shape Monk (hint: it should be!)

[eggs]

Spirit Bind a couple dozen Faerunian Nagas and laugh and laugh.

[Gavinfoxx]

As far as the Monk side, a Wild Monk, Holy Strike, Invisible Fist, Resistant Body (Fire), with Exalted Wild Shape, Frozen Wild Shape, Draconic Wild Shape, and Touch of the Golden Ice would be pretty good in melee!

[Gavinfoxx]

Wu Jen has Gate, Shapechange, Summon Elemental Monolith, Summon Monster IX, Time Stop, Energy Immunity, Giant Size, Greater Teleport, Globe of Invulnerability, Mind Blank, Animal Growth, Astral Projection. Do the math yourself.

Also several scrying spells.

The Wu Jen scries the area of the Dragon, buffs up themself and their Wild Cohort, turns themself (and their Wild Cohort) huge, gates in a bunch of allies, wild shapes, shapechanges, and greater teleports to the Dragon, and then slaughters it.

[Randomguy]

You don't really need wild shape when you've got shapechange. That said, it's nice to have since, unlike shapechange, it can't be dispelled.

Keep in mind the dragon's most powerful ability: Spellcasting as a level 19 sorcerer. Get stuff to stop your spells from being dispelled, like a ring of Enduring Arcana. Make sure you have something to stop disjunction, too.

Dragons have good SR and great saving throws, plus Wu-Jen don't have many blasting spells, so it looks like your best strategy would be to kill it in melee, or to summon things to kill it.

If you go melee, buff up as much as you can before going up against the dragon. Elemental immunity to everything possible would be nice, since if the dragon knows Breath Weapon admixture and you've only got Fire immunity then you're in trouble. Mind blank will let you ignore the fear aura and any mind affecting spells.

Use shapechange to turn into something strong, like a Titan, balor or Pit fiend. Titan gets you the higher strength, but Pit Fiend gets you a bunch of natural attacks in addition to your normal full attack routine, as well as more natural armour. Balor isn't really that good in comparison, I think, but they get true seeing which might be useful.

Then on top of that put Giant Size, Metal Skin, Magic Circle against Evil, thornskin, Greater Magic weapon (on your natural attacks), haste, scales of the lizard (it stacks with metal skin since metal skin is an untyped bonus), displacement, globe of invlunerability, Body outside body (cast this one after all the other buffs so that your clones have buffs too), shield and anything else you think might be useful.

Extending some of the spells might also be a good idea.

Make sure you have a teleportation spell prepared for a quick escape, dimensional anchor to stop him from getting away, and possibly dismissal if he summons anything.

[eggs]

Speaking of Dimension Anchor, summoning an Orthon from Fiendish Codex 2 (via SM 8) is pretty worthwhile, by the way. It partially covers for the Wu Jen's lack of Dimension Anchor with a Supernatural (ie. SR: No) dimension lock-type power. Summon one, then have it spend its turns readying actions to match opponents' movement (against a Dragon's fly speed, you might need to summon it on top of a Spirit Bound Lung Dragon), or just have it stand about while you get your Greater Spirit Binding debuffs/charisma checks happening.

It still might be worth jumping through a hoop or two for the actual Dimension Anchor spell, though (Arcane Disciple, UMD+Runestaves, Recaster, or whatever trick you're more comfortable with).