Scrap Fist - Legendary 5D'

Target 1 "Junk Warrior" you control; if it battles an opponent's monster this turn while you control it, 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.
• It cannot be destroyed by battle.
• Destroy the opponent's monster that battled it at the end of the Damage Step.