Fusion-Substitute Monsters (融合素材代用モンスター, Yūgōsozai Daiyō Monsutā) can be used as replacements for specific Fusion Material Monsters listed on a Fusion Monster, as long as the other monster(s) used are the correct one(s) for the Fusion Summon. The Fusion Substitute Monsters are used as direct replacements when using "Polymerization" and "Fusion Gate" for a Fusion Summon.
Fusion Substitutes cannot be used for:
- Fusion Monsters that can only be Special Summoned from the Extra Deck by removing the Fusion Material Monsters listed on it from your field (Contact Fusion), such as with the "Elemental HERO Neos", "Gladiator Beast", and "VWXYZ" Fusion Monsters
- Fusion Monsters that state, "A Fusion Summon of this card can only be conducted with the above Fusion Material Monsters", like "D.3.S. Frog" or "Cyber End Dragon".
- A Fusion Summon conducted with "Future Fusion". This is because Fusion Substitute Monsters have no effect while in the Deck.
- Fusion Monsters that do not specifically name their Fusion Material Monsters, like "Ojama Knight" or "Evil HERO Dark Gaia".
- If the Fusion Monster has both specifically named and unnamed Fusion Material Monsters (like "Ultimate Ancient Gear Golem"), then you can use a Fusion Substitute Monster, but only for the specifically named Fusion Material Monster.
Fusion Substitute Monsters
Regarding Elemental HERO Prisma
"Elemental HERO Prisma" is not considered a Fusion Substitute Monster; its effect makes the card's name treated as the sent monster's. Therefore, "Elemental HERO Prisma" can be used as a Fusion Material Monster for cards with strict Fusion Materials, such as "Cyber End Dragon" and "Cyber Blader". As it is not considered a Fusion Substitute Monster, "Elemental HERO Prisma" can be used with a Fusion Substitute Monster to perform a Fusion Summon.
Some things to remember while using "Elemental HERO Prisma":
- The Material must be from the Main Deck. You cannot show "Elemental HERO Shining Flare Wingman" and send "Elemental HERO Flame Wingman" to the Graveyard. In this case, you would have to send "Elemental HERO Sparkman". You would not be able to show "Naturia Exterio" at all because all the Materials are originally in the Extra Deck.
- The Material must be written out on the card. Like Fusion Substitute Monsters, "Prisma" requires the Fusion monster to specifically name the Material that "Prisma" will imitate. For example, you cannot show "Five-Headed Dragon" at all because it does not specify any one monster.
- "Elemental HERO Prisma" assumes the name of the Material in question. As such, it is considered a "proper" material instead of a Fusion Substitute Monster for all purposes.