Can you clear it within 13 minutes?
My attempt at a character.
Azurin
Fighter 1//Cloistered Cleric 1
14
10
16
14
12
12
Able Learner, Shape Soulmeld - Therapeutic Mantle, Divine Metamagic - Persistent Spell, Persistent Spell, Martial Stance - Martial Spirit, Extend Spell, Extra Turning, Knowledge Devotion, Willing Deformity
Shaky & Vulnerable for flaws.
Next level has a lot of options, either go with fighter for dungeoncrasher or crusader, retraining Martial Stance to something else, maybe a deformity. If I go with crusader, dragonfire adept would go other the other side, and then I would select dragonscale husk. Fighter has more options, could grab binder for ability healing, warlock for an invocation, incarnate for a second meld (retraining Shape Soulmeld), rogue for trapfinding (most likely grabbing a feat instead of sneak attack), or a level of factotum.
Think it would hold up to the riggers of the dungeon?