Scrap Fist

Target 1 "Junk Warrior" you control; this turn, if it battles an opponent's monster, apply these effects. - Your opponent cannot activate cards or effects until the end of the Damage Step. - If it attacks a Defense Position monster, inflict piercing battle damage to your opponent. - Double any battle damage your opponent takes from battles involving it. - It cannot be destroyed by battle. - Destroy that opponent's monster at the end of the Damage Step.