Urthemiel, the Destroyer

In a time before mortals began to record their history, gods and primordials battled each other in the Dawn War. Each side wished to be worshiped by mortals and gain power from the mortal's faith and prayers. They fought fierce battles, unleashing cataclysmic magic and terrible weapons against each other. The gods, in a bid to turn the tide to their favor, made a creature so powerful it could lay waste to entire worlds as a living weapon: the Tarrasque. After suffering several defeats where the Tarrasque's presence turned the tide of battle, the primordials responded with a creation of their own: Urthemiel, the Destroyer.
The two titans clashed, Urethemiel's lightning against the Tarrasque's fire, as the gods and primordials watched a level of destruction that gave even them pause. The collateral damage began to destroy the worlds of mortals, the very worlds the gods and primordials wished intact to claim as their prize. But the two beasts proved to be as tame as rabid dogs, striking out at their creators as well as their enemies in the frenzy of battle. They could not be contained without risk and none were brave enough to approach them.
So the two sides brokered an unspoken truce and did the only thing they could; they waited. Eventually, the beasts fought themselves to exhaustion and collapsed, unable to either move or finish each other off. It was then the gods and primordials made their move, sealing their terrible creations away beneath the earth they lay on before resuming their battles. And so Urthemiel lay dormant...for a time.
While the primordials did imprison Urthemiel, the waning their magic suffered after losing the Dawn War caused the seal they used to lock Urthemiel away to begin weakening. The gods knew that Urthemiel's seal was unlikely to last forever. And so they created The Four, legendary weapons that together would give mortals a fighting chance against the weakened Destroyer. The weapons were made to lay dormant until Urthemiel began to awaken, and already two of The Four have been found. Urthemiel will soon break free from his prison; whether the world of Nexus and countless others will survive his reemergence, only time will tell.