It's pretty nice! I found it very overwhelming at first: so many moves available... but 90% of my turns were Fireball :/ Limiting the player's choices each turn could've made it both easied and more varied.
I don't think I quite understood how swap abilities work: a preview on what the amounts will be after using the ability would help greatly!
But a significant balancing factor was that no moves swap with health. No hit is an instant-kill: all that's left is juggling mana and energy. This feature I appreciate much!