in the various Well World
sagas, by Jack L. Chalker
. Little is actually known about Nathan Brazil, except that he is immortal
, is the only person (until later in the books) who has root
access at the Well of Souls
, and is a lying scoundrel
At various points, he has claimed to be God, the last Markovian technician, the Wandering Jew, and a poor schmuck who got suckered into being the guardian of the Well. He has the capability to alter reality in a controlled fashion when in the Well, including setting other people up with this power, and rebooting the universe.
Since he is a product of an earlier universe, and the caretaker, the Well, which runs the universe, will not allow him to die.