Once per turn: You can discard 1 card; add 1 "Polymerization" from your Deck or Graveyard to your hand. Once per turn, during the End Phase: You can target 1 monster in your Graveyard that was used as a Fusion Material for a Fusion Summon this turn; add it to your hand.
This will combo nicely with Geartown. Because it's a field spell, Geartown will be destroyed when you play it, meaning you can summon a free AG monster from the deck. This sets you up for an easy UAGG.
The problem with a field spell is that for fusion there's a good field spell, fusion gate, even though it does banish your cards, I still think it's better, because you don't need to discard a card, and then you can keep fusing without restrictions