Recently, I played in an epic level 3.5 game. When constructing my 30th level character, I had to give some serious thought to this sort of thing... just what motivates a character who has risen to such heights? What drives this sort of being to adventure, rather than sit back on a pile of accumulated wealth?
It helped that I was playing an evil character. Beldrachor had been a tyrant emperor until his people rose up against him, mummified him, and entombed him alive. He became undead, and lay dormant in his tomb for ten thousand years until he finally escaped. His goals were for power, but he realized that mortal power was fleeting; the only true power lay in ascention to godhood.
Beldrachor's pursuit, however, did not require him to save the world. It was a quest to gain the knowledge and power to take down a demigod and rise up in their place. Being immortal, he had all the time in the world to lay his cunning plans. He would bide his time, and when the moment was right, he would ascend.
