Azure Fang
Green Slime
This one is pretty specific. On the fourth floor of arcade mode, in Perfect Guard challenge rooms, a desync can occur if - and only if - the enemy selected for the challenge is a Pecko. Said Pecko will randomly target the wrong player, making it extremely difficult to complete the challenge. We have seen this behavior both as host and client, with one session having both players Peckos desync and attack the opposite player in a single room.