Marvel comics: I am the One Below All.

The One Below All is the direct and opposite counterpart of the One Above All. This has radically altered Marvel's cosmology since this makes the One Below All Marvel's first true Anti-God and as such, it is the unequaled embodiment of destruction, wrath, and ruin. The One Below All is also the true power behind the mutagenic factor of gamma radiation in Marvel, creating the gamma mutates (of which Hulk is obviously the most famous and powerful). It was this very revelation that drove Brian Banner insane as he believed his son carried a monster gene, having caught a glimpse of the One Below All during his own experiments into gamma radiation. The One Below All is the alter ego and other face of the supreme creator and God the One Above All. Just as there must be creation there must also be destruction and the One Below All's purpose is to be the destruction in the cycle of death and rebirth in the multiverse. While the One Below All is a separate identity from the One Above All, they are both halves of the same being and as such as a counter/foil to the other. Each time a multiverse is created by the One Above All, entropy begins and the One Below All influences all the destructive beings in the multiverse to push everything to destruction.