This was great! My first run through I lost at I think battle 16 and unlocked 3 other characters. I quickly learned that having multiple mana types was problematic for strategy, so I picked only Velrach and Jasper. Before long, I built a cheese with some key upgrades to win every fight in one turn:

1. +2 extra mana when stealing 1 mana
2. "simulate the attack of a random ally" (only 1 other ally)
3. ignore taunt (wasn't necessary, but I predicted that, after a while, it would be, so you can recharge off a 1-mana enemy when necessary)
4. Always pick coins (not health) - you never get hit!

from there you just keep stacking +dmg upgrades (on either character, but Velrach got more of them).

The interplay between upgrade predicates (especially between characters) reminded me of Balatro jokers. If you built this game up I'd probably buy it!

Good game! I wanted to sit for 5 minutes and eventually lost track of time :)

I really like the gameplay, it's easy to understand, but hard to get good at. Very good game overall.