Transformation Summon

A Transformation Summon (変（へん）身（しん）召（しょう）喚（かん） Henshin Shōkan) is a type of Fusion Summon featured in the Yu-Gi-Oh! GX manga. It is used by the "Masked HERO" archetype.

It essentially reduces the amount of cards used for a Fusion Summon by one, in that only one monster and a card such as "Mask Change" or "Form Change" is needed, as opposed to two or more Fusion Material Monsters and "Polymerization". However, the produced Fusion Monster tends to be less powerful than the result of a traditional fusion.

Trivia

• Although Jaden Yuki does not perform Transformation Summons in the Yu-Gi-Oh! GX anime, he does use "Metamorphosis" and "NEX", both of which effectively use only one Fusion Material to summon Fusion Monsters that can only be summoned this way. These are "Elemental HERO Neo Bubbleman" (which was a Fusion Monster in the anime), "Elemental HERO Clay Guardian", "Neo-Spacian Marine Dolphin", and "Neo-Spacian Twinkle Moss".
• The TCG/OCG effect of "The Eye of Timaeus" resembles the mechanics of Transformation Summon.