I don't think there's any bugs. But I would like to know what the recommended levels would be at before fighting the Pufferfish Priestess and Queen Coraline? It's because they're still difficult to beat even when the team is at level 13.
Also, is there any way to obtain the Liquid Metal Blade in the game? Because I open this chest in this debug room, not knowing about it even when I've equipped to someone, until I've started a battle, and when doing a basic attack, it did so much damage! https://postimg.cc/qh146TrJ