De-Fusion
Quick-Play Spell
Return 1 Fusion Monster on the field to the Fusion Deck. In addition, if all the Fusion-Material Monsters that were used for the Fusion Summon of that Fusion Monster are in your Graveyard, you can Special Summon them all to the field.
A bit of an overlooked card that may not be as useful not that "Magical Scientist" is banned, but can still provide a good countermeasure against "Metamorphosis". The first part of its effect returns a Fusion monster back to the Fusion Deck. Great. Take that pesky "Thousand-Eyes Restrict", activate this when he tries to take your monster and kick him back.
The second part of the effect only works in a dedicated Fusion Deck revolving around "Polymerization". Whatever you used with "Polymerization" can be brought back to the field from the Graveyard (but only if they are all in the Graveyard otherwise you get nothing). This can be useful for recycling a Fusion Substitute monster or if you want to bring several heavy hitters back to the field. Assuming you also used no substitutes for your fusion, if you get a clear shot with any of these 3 Fusion Monsters:
"Dark Paladin"
"B. Skull Dragon"
"Master of Oz"
You can use "De-Fusion" on them, attack with the monsters that made them, and win the round (since you will do at least 8000 damage).
"De-Fusion" is a very techie card that is either a decent side deck or a main deck for a Fusion deck.
Quick-Play Spell
Return 1 Fusion Monster on the field to the Fusion Deck. In addition, if all the Fusion-Material Monsters that were used for the Fusion Summon of that Fusion Monster are in your Graveyard, you can Special Summon them all to the field.
A bit of an overlooked card that may not be as useful not that "Magical Scientist" is banned, but can still provide a good countermeasure against "Metamorphosis". The first part of its effect returns a Fusion monster back to the Fusion Deck. Great. Take that pesky "Thousand-Eyes Restrict", activate this when he tries to take your monster and kick him back.
The second part of the effect only works in a dedicated Fusion Deck revolving around "Polymerization". Whatever you used with "Polymerization" can be brought back to the field from the Graveyard (but only if they are all in the Graveyard otherwise you get nothing). This can be useful for recycling a Fusion Substitute monster or if you want to bring several heavy hitters back to the field. Assuming you also used no substitutes for your fusion, if you get a clear shot with any of these 3 Fusion Monsters:
"Dark Paladin"
"B. Skull Dragon"
"Master of Oz"
You can use "De-Fusion" on them, attack with the monsters that made them, and win the round (since you will do at least 8000 damage).
"De-Fusion" is a very techie card that is either a decent side deck or a main deck for a Fusion deck.