WARNING! SPOILERS AHEAD!
So I have gone far enough into the game in my experience and I would suggest a few balancing fixes about some of the harder fights in the late game.
The first time I noticed a fight to be much more reliant on luck is when I fought the Queen Bunny in the casino(which is also better named "Bunny Queen" in english, but it doesn't matter).
The annoying thing about that encounter is that if you randomly get grabbed 3 times you automatically lose not because you get much weaker, but for the fact that the enemies completely refills their health, thus making the fight impossible. Other than that detail, I think the fight is balanced.
The second annoying fight I encountered was against Fu, the fighter guarding the vampire dungeon entrance in the bottom right of the castle.
The mechanics in this encounter are interesting and you can't just brute force this fight with dps, rather you have to pay attention to your current debuffs. The main issue here is that the enemy gets to play not once, but twice per turn. This is the most frustrating factor of this fight as the enemy can do whatever they want and you have little to do about it.
If she uses twice the Nightmare Sly, it's pretty much a oneshot. If she spams the agility debuff you are also fucked because you have to remove it as soon as possible to avoid being drained and the fact that she gets to act before you means she can drain you in that instant and this does not enable any counterplay from the player.
The same issue (2 turns for enemies) can be said about the fight against Leena, the second mermaid as she has such good stats that she can outheal any of your damage . In particular, dealing damage to her with the strongest of my abilities would deal like 10k damage and she would heal for like 25k health per cast, making this another unbalanced encounter in my opinion.
Finally, the last fight I found myself stuck at the duo fight against the mermaids as if you get stunned in any way possible you get drained and success chances lower by a lot.
As I was writing this message, I gave the duo fight a few more tries and I managed to barely get past it using a combination of the Tornado ability spam and hoping for critical hits. I still think that this duo fight is also unbalanced as the enemies have plentiful ways of stunning you at any time.
In my experience, the fights mentioned above were quite frustrating to get past, especially the Fu one so I would suggest giving them some changes. Still, I'm not a game developer and I only wanted to share my thought as a player. I also think that the scenes are well-made and the game's mechanics are quite unique from the plenty other games I played.
