Evolution

If possible, this card's original passives change rarity based on its HP: the lower its HP, the rarer they are. Thresholds at 75%, 50% and 25% HP. Target rarity based on current HP: Above 75%: common. Above 50%, up to 75%: rare. Above 25%, up to 50%: epic. 25% or less: legendary. A variant of the same passive and element must exist at the target rarity. Otherwise, the passive stays unchanged. Passives added during the game are excluded, as are Mystery, Metamorph, Random Metamorph, Discovery, Corrupted Heart and Thief.