I'm surprised that people are struggling with the combat. All you have to do is optimize your equipment and then use the the regen spell after Luna takes two hits and you're golden for every fight.
The boss floor can be a little tricky but if you bought like 5 herbs from slime girl's shop to the left you should be good to clear as using those as last second heals.
The boss floor can be a little tricky but if you bought like 5 herbs from slime girl's shop to the left you should be good to clear as using those as last second heals.