Once per Duel, you can discard 1 card to Fusion Summon 1 "Ancient Gear" Fusion Monster from your Extra Deck, using monsters from your field as Fusion Material. If 1 of those materials is an "Ancient Gear Golem" monster, you can also use monsters from your hand and/or Deck as the other material. Your opponent takes no damage for the rest of this turn. Any battle damage your opponent takes from that Fusion Monster is halved.