The battle system is a little weird, I couldn't see anymore in game explanation. How come bird cards don't heal me? The tutorial explained that if I an attacked by a +3 card, and I use a +2 bird card to heal, I should only take 1 point of damage, but everytime I try to heal with a bird card in nightmare mode and regular dates, I just take 5 damage, or whatever is the damage of mine and opponents card combined. Did I miss an explanation or is this a glitch?