Amnesia

The uses casts a memory wiping spell.

The target must make a wisdom saving throw. if succeeded, the target will only forget about the fight for an hour. if failed, they will forget about the entire campaign for an hour. they will also had disadvantage on perception checks, due to the target forgetting who they trust. when the spell ends, they must make a charisma saving throw. if they succeed, they remember everything fine. but if they fail, they will slowly get it back, until a short rest, where it will fully recover  

when cast at higher levels,  they will forget for an additional hour