Polymerization

If this card is in your hand, exile all fusion monsters in your deck. This is not optional
and cannot be countered.

You may cast this sorcery in order to cast a fusion creature from your exiled zone without paying its mana cost, by sacrificing the fusion materials listed
on it from your hand or field.
This can be done only if target fusion creature has been exiled by its own effect or by the effect of Polymerization.