(Good day Devs) when would it be possible for evie to get possessed and how about being able to walk around the map naked because a ghost crew from captain ceres phantom pirate named Penelope was able to walk around the map naked when Penelope was possessing Celica
So far, there is no information regarding ghosts taking over Evie's body. If such a possibility arises, we will only find out about it once it happens; Deimus doesn't like to spoil the surprise ahead of time.
As for naturism... There is the Dark World and a specific artifact for that, which must be equipped before battling monsters.
Walking around unclothed in Granoria itself is dangerous—at least for the time being. So, if Deimus decides to rewrite these mechanics, we will find out only when it actually happens.