Fusion Substitute Monster

Fusion-Substitute Monsters 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, 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.
 * 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.

Also, you can only use one Fusion Substitute Monster per Fusion Summon.

Regarding Elemental Hero Prisma
"Elemental Hero Prisma" is not considered a Fusion Substitute Monster; its effect makes the card no longer treated as "Elemental Hero Prisma", and instead it is treated as the sent monster. So, you are able to use "Elemental Hero Prisma" as a Fusion Material Monster for cards like "Cyber End Dragon" or "Cyber Blader". You can also use "Elemental Hero Prisma" and a Fusion Substitute Monster to perform a Fusion Summon.