To see the worlds that he had created come into ruins was not fun. He would have accepted it if only one was destroyed but during the course of those years, multiple worlds were already destroyed. The god of creation already sent heroes to destroy him but they couldn't put a dent on his magic.
Cygnus was already so strong that they had a difficult time dealing with him. One more annoying thing that he had was his ability to travel in different worlds even though he did not have the gift. The immortality that the demon has given him made it possible for him.
After a few hundred years, finally a human was able to wield the power of space and yet she became a subordinate of Cygnus. The gods tried to meddle and made her hate him but the woman was resilient and did not give in. She was then separated from the group and they sent people to go after her but they lost sight of her.