Gandora-X the Dragon of Demoli

When this card is placed on the field from the hand: You may destroy as many other creatures on the field as possible, and if you do, inflict damage to your opponent equal to the highest original Mana cost on the field among those destroyed creatures (your choice, if tied). This card's gain +X/+0 where X is equal to the damage inflicted to your opponent by this effect. Once per turn, during your End step: Halve your Life.