Number 52: Diamond Crab King [YZ06-EN001] Ultra Rare

2 Level 4 monsters
Cannot be destroyed by battle except with "Number" monsters. You can detach 1 Xyz Material from this card; decrease this card's DEF by any amount, and if you do, this card gains ATK equal to the same amount, also if this card attacks a Defense Position monster, inflict piercing battle damage to your opponent. These changes last until the End Phase. During your End Phase: Change this card to face-up Defense Position.