Reveal 1 Fusion Monster in your Extra Deck, add 1 of the Fusion Materials listed on that card from your Deck to your hand, then you can add 1 "Polymerization" from your Graveyard to your hand.
Fusion Recycling Plant can recycle 1 fusion material monster to your hand, and also search for Polymerization from your deck. King of the Swamp can be treated as 1 fusion material required for Fusion Summon, and at the same time it also can be used to search 1 Polymerization from your Deck. Fusion Sage can search 1 Polymerization from your deck.
Here are decks that rely on fusion summoning, making Fusion Reserve a great search and consistency boosting option. Although in the case of Gladiator Beasts you only use this card for its search effect, you cannot use recover polymerization from the graveyard as Gladiator Beasts generally don’t use fusion cards.
|Actions||Reveals your Extra Deck / Adds from Deck to hand / Adds from Graveyard to hand|