Enter Oblivion

OBLIVION AND BEYOND
Breaking a bargain with a god is impossible, or so they say.
Which means Hannah is Cthulhu's forever. But she still hasn't learned to use her powers at will and old Tentacle Face isn't happy about it. His minions drop Hannah at Cain's doorstep with orders—make her useful in a month, or she dies.
Cain isn't sure what's worse—damning her to an eternity serving Cthulhu, or letting her die. No matter what he does, he'll lose her.
But a wizard and a dwarf have a proposition: Trade Cthulhu something of greater power than a demigoddess. It just so happens they know exactly where to find such a thing—on a dead world the gods abandoned eons ago.
The world of Oblivion was created before Gaia. A war between the gods destroyed most life and left it a desolate, dangerous wasteland. Hidden somewhere on that world is the lost armory of Hephaestus. It is said to contain super weapons created by the blacksmith of the gods. If Cain can locate it and procure such a weapon, Cthulhu might be willing to make a trade.
There are others also looking for the armory. Among them are the mechanists, a faction that despises magic and wants to destroy the gods with their own super weapons. Their clockwork devices are unlike anything Cain has faced before, and they're the least of his worries.
But Hannah saved Cain by trading her freedom for his life, and he'll enter Oblivion itself if it means saving her.