I hate my crappy markers
_______

In a multiverse since long condemned, two deities were fighting. A God, the creator of all the mortals, and a Satan, the adversary, supreme lord of evil of that multiverse. The former was stronger than the latter, and things were good for a long time. Until the situation plummeted. The Lord lost against the devil, and they merged in a single entity. Neither of them was strong enough to handle their combined powers, and so both their minds were corrupted while fusing.
It believes to be the supreme good, the most benign being in all existence, to the point that anybody else is evil and therefore deserves to be erased from the realities.
But it didn't decide it right away. At first, it believed everyone deserved to be punished, and so it twisted all the inhabtants of its multiverse to its deviated vision. Angel, devils, demons and celestials, no one escaped the punishment of the pious scourge (it says it is pious becuase he doesn't identify with God anymore, but it brings onward its vision most perfectly).
When all the beings of its multiverse were "fixed" it decided to move to other realities, other multiverses, looking for beings worthy to be saved. But no one ever fits the canons it has set, so every one is doomed to be destroyed.
It usually lets it twisted legions do the job, but it steps into action from time to time, if it feels like it.
It has godly powers, but can't see the future and it's not omniscient, because those powers are limited to its reality.