After seeing what happened in the war between the celestial king and the demon lord, and upon discovering that the war deities created demon, the gods of creation were angry.
Then the king of all the gods of creation sent a messenger to the king of all the gods of destruction to kill all the demons they created, and if not there will be war at any time and it'll be best they prepare, in response to the message the king of all the gods of destruction executed the messenger.
After thousands of years when the celestial king died and the gods of creation discovered that it was the gods of destruction that did it, war broke out.
The war was so intense they destroyed the two realms they live in, even destroying the hierarchy itself.
After fighting for years the war ended with the gods of destruction winning. And with no place to reside they created a place called OBLIVION. That place became their new home, Some of the gods of creation that survived the war created a golden palace they called HEAVEN, and they made it in a place that not even that gods of destruction could find them and they lived in it training every single time to one day take their revenge on the gods of destruction.