It was important to note that the three God Curses never lost their physical body. Not even Fenrir's body was taken away and destroyed when he was caught and transformed into a Curse. The bodies were pushed into the Curse's Essence, where they were kept and maintained. Another interesting fact was that the Curses couldn't escape the seal without destroying their bodies. Each Curse had certain conditions to unlock its first seal, but all of them had one thing in common:
They could break out of the Curse if they were willing to cripple their bodies. Fortunately, Fenrir hadn't been pushed this far before encountering Michael, otherwise, the following events would be a little bit more difficult than they had to be.
Michael accessed the Expanse System and searched for the Curses sealed in the void of the Expanse. He saw a handful of God Curses and a lot more lower-ranked Curses but didn't pay too much attention to them at first.