Gaia Dragon, the Thunder Charger (GAOV-EN046) [Galactic Overlord]

2 Level 7 monsters // You can also Xyz Summon this card by using a Rank 5 or 6 Xyz Monster you control as the Xyz Material. (Xyz Materials attached to that monster also become Xyz Materials on this card.) If this card attacks a Defense Position monster, inflict piercing Battle Damage to your opponent.