Maybe there could be a new curse enchantment that when an entity or player is wearing it ethereal players can possess them even if they still have a soul! This is just a fun idea though it is not very important so don't stress about it it's fine if it isn't do-able!

Originally posted by @Dunk0w0 in #500 (comment)

I think it may be better to add a new soul effect called Faintness, every creature with this effect can be possessed by ethereal player in a limited time (configurable), the higher level it is, the more time and the less interval it can be possessed.

that's not a bad idea. the reason I was suggesting it to be an armor enchantment was because it was based off of someone else's suggestion of being able to possess armor stands which I think could be a cool idea. But your idea is also neat!

Alternatively, the curse can allow ethereal players to possess other players or mobs, even if they still have a soul, but the entity retains some control of itself even when possessed.

For example, a player possessing a pillager with the curse (that still has its soul) can turn its head and nudge its body a bit, but if the pillager was trying to attack a villager, it will continue to do so of its own accord even while being possessed.

Similarly, attempting to possess a piglin with the curse to get it to attack a Zombified Piglin or go through a Nether Portal may cause the piglin to run away on its own, even if it is still being possessed, unless the piglin's soul is removed.

@James103 ooooh that would be really cool!! From the dev's pov that might be hard to add but I don't know for sure since I'm not one of the devs. But if they are up for adding it then I do think that would be pretty cool!