I did not even finish the very first battle. AGES without getting anywhere - I am out.
Adding cooldowns AND nerfing the shield leads to unbalanced fights that are all a guaranteed loss for us except for the very first one of the day when our levels are full.
A typical fight, even against the lowest kind of demon, goes as such:
You have twice the HP of the demon. You feel confident about the issue.
You hit. Demon takes 2 HP damage. You feel even more confident.
You cast your spell. Demon blocks: zero damage for him PLUS he gains energy.
You generate energy bc you're at zero. Demon kneels and regenerates 3 HP.
You cast again. Demon blocks again then kicks with his fist/foot, USING NO ENERGY in the process. You lose 2 HP.
You generate energy bc you're at zero. Demon casts and hits for 5 HP. You feel like Heck wtf. By then you and him have the same HP.
Rinse and repeat, after another 40 minutes of "fight" with you having to regenerate energy half of the time while Demon hits (spell or kick) each time or kneels and regenerates more HP than what you damage him, you see your HP bar going to zero while you can't do anything to refill it, bc unlike the Demon you have zero way to regenerate HP.
You're dead. You curse the dev. You leave/erase the game or you load your save, hoping that the tenth attempt of the same fight will end better than the first nine.