ゆうごう 融合
[b]Polymerization[/b] is a normal-type "spell card":https://yugioh.fandom.com/wiki/Spell_Card in the [[yu-gi-oh!|Yu-Gi-Oh!]] trading card game. This card allows its user to "Fusion Summon":https://yugioh.fandom.com/wiki/Fusion_Summon one "Fusion Monster":https://yugioh.fandom.com/wiki/Fusion_Monster from their "Extra Deck":[https://yugioh.fandom.com/wiki/Extra_Deck] by fusing monsters from their hand or their side of the field. As it is the main way to summon most of the powerful Fusion Monsters, it is a staple in the deck of many main characters, including [[Muto Yugi]] and [[Yuki Judai]].
polymerization