Absolutely loving the game, had a couple of card ideas.
Double edged sword: Value - 0. On play: both players choose a card from their play, draw, or discard pile to burn, then burn this card.
Overheal: Value - 3. On play: lock. On heal: if you are at max heath, deal the healing as damage to your opponent and unlock.
Broken heart: Value - 5. On play: lock. On health reduced below 0, heal to 1, lose that much max health, and permanently remove this card from your deck.