Well, when you have ultimate power, the instinct should be (I think) to take advantage and play whatever high-powered thing you want to play.
That said, some thoughts:
A) First Side:
* Binder 1/Thaumaturge 4/Anima Mage 10 for one side gives very flexible spellcasting and all-day endurance
* Play a monster at Level = CR+1 or +2. Elemental Weird at 14th level is pretty awesome, winning the information game. Astral Projection to adventure. (I'd use an item, with 9th level slot = Wish)
* Conduit of the Lower Planes 5, expert access to Sphere: Magic -> Limited Wish at will (at will casting of 6th level arcane, 5th level divine) as spell-like ability. ... Conduit of the Lower Planes 5/Ur-Priest 2/Progression 8 (Lord of the damned 10).
B) Second Side
* Sohei 5/Enlightened Disciple of Wel Hung Temple 10 - pure awesomeness: cool immunities, can't be interrupted by standard actions, mindblowing buffing and retributive magic effect via "Enlightenment: We Are All Connected", stat bonuses from Half-Celetial.
* Ninja 15 (surprise round master is awesome)
* Fighter 15 (what's not to like?)
I'd probably play an Elemental Weird / Enlightened Disciple.
Best,
David