I love the concept, and it reminds me of Slay the Spire. I think it would be interesting to play with cards that affect my luck, like a card that buffs the probability of my next spell succeeding if it succeeds, or debuffs it if it fails. With this system, you could add cards that are beneficial when luck is against you. (For example: if you have a luck debuff, you could choose a card that deals damage to the enemy if you hit 8 or less, and deals damage to you if you hit 9 or more). Nice submission!