Engine Power Over-Limit!
Select 1 Rank 10 EARTH Machine-Type Xyz Monster you control. Then, attach 1 Level 10 EARTH Machine-Type monster in your hand to this card as an Xyz Material. If this Xyz Monster attacks a monster in Defense Position during this turn, inflict piercing battle damage to your opponent. Send that Xyz Monster to the Graveyard at the end of this turn. This Skill can only be used once per Duel.