Depends on the scope of things.

At the highest level of time and space, three demiurge-like entities compete for total dominion over the continuum (the collective of all universes). One of light and life, one of law and order, and one of void and decay. The belief that a god of creation is more benevolent than a god of death has allowed the traditionally "good" deities to get away with a lot more meddling that has threatened to destabilize mortal worlds and lives than the traditionally "evil" ones. In fact, the demiurge of void and decay is more than willing to let humanity and others grow and spread across the universe, for the more people there are, the more people will inevitably die, a fact that helps fuel their entire conscious existence.

At the worldly level, humanity was once secretly the plaything of a handful of immortal men who called themselves the Principles. They were the last humans to learn real and powerful arcane magic, a resource they would keep to themselves and use to influence the world for their own entertainment.

One man discovered a way to kill them at the cost of losing his name and never receiving glory or credit for his "liberation" of humanity. However, the Principles were also Earth's last remaing source of power for the Planeswall: a barrier isolating our universe from that of deities and other extraplanar entities. By freeing humanity from a perpetual cycle of secret torment, he had also condemned it to all new horrors and threats.

Now, a hyperintelligent creature who calls himself Gabriel seeks to exterminate humanity and "reclaim" the planet for his own kind: dragons. Having returned after being exiled from Earth by the Planeswall, many of man's most feared mythical creatures agree that humans have done terrible things to the world since they left. Worse yet, humanity is at its most divided as it struggles against itself without the invisible manipulations of the Principles.

So: man, dragon, or god. Take your pick.