The Cascade
Killing Abbadon and fighting Mordenkeinan sets of a chain of events:
The gods begin to take severe injury. Reincarnation slows, reports of no births, etc. You see visions of their world. Two massive titans, a fiery, blinding woman fighting alongside her brother, Elatha, the moon god. They are shin deep in a strange ocean of their own blood. Dozens and dozens of the alien creatures bombard them, exploding onto their flesh. Every so often, their focus must shift from the battle to perform some magic, keeping the cycle of life in the material world on.
Mordenkeinan flees, being the last thing between them and true Apotheosis. He wants to kill them as much as they do him.
Renaxis grows worried. He does say he will ascend too, he is joining them. At tier 2, he will break free.
A clue can be found about the origin of the aliens. They relate to the starfallen ore. The starfallen ore can be used to teleport through their voids, into their realm. The void can be closed, but only from the inside. They cannot fully ascend, they need to travel into the heart, and take it out from the source.
- From Mordenkeinan or Nystul they can learn of the weakness.
Renaxis will sacrifice himself to save the party from Mordenkeinan. He tells them to pass his name onwards, do not let him die in vain.
Upon killing Mordenkeinan, there is an immeadite shift. Each characters dies, is brought to Death, and their soul taken, instead of being put back in the river, is ascended up, torn apart, thrown into the air like ash. You reform, sensing every thing in the world, you are now full gods.