Due to this, a cult was formed in order to collect the souls of humans who were sacrificed to the cause of keeping him asleep, willingly or otherwise. This has become known as the "Doomsday Followers" and this cult has a global presence.
All the cultists share a common trait amongst their members: Dark, and possibly bloody robes, ritualistic daggers and a mask shaped in the likeness of Perfect Memento himself.
If a cultist has appeased Perfect Memento enough times, they will mutate and take on a much more terrifying form as a result. It is unknown to what actually happens to these mutated cultists, but there is a theory that they eventually become a Doomsday puppet.