Enuo (Final Fantasy V)

In Final Fantasy V, Enuo was considered to be the ultimate evil, and if the people of the time-travelling village are to be believed, a fool as well. He was essensially a god; in that he was immortal. He decided that this was not enough for him, and traded in his immortality for access to The Void. However, the Void cannot (reportedly) be controlled, and he was consumed by the raw power.

The main enemy of Final Fantasy V (Exdeath) has the "soul" (or what can be considered as such) of Enuo; as such, Exdeath's atempts to control the power of the Void make Enuo seem a glutton for punishment. Ironically, Exdeath was also consumed by the power of the Void, and so his plan failed a second time (a third time if you count the fact that Exdeath was defeated by the first generation of light warriors before the events of Final Fantasy V).

Enuo is also a secret boss that can only be fought after the completion of the main game (thus, while his spirit is destroyed, this is not true to the storyline); he is fought deep inside the Void which makes us assume that those absorbed by the Void do not essensially perish.