Carnage Unity is one of the systems featured in Tokyo Mirage Sessions ♯FE. Carnage Unity consists of using materials earned in battles or found in dungeons to create new weapons called Carnages for Mirages to wield. Equipping these weapons allows the Mirages to learn skills or power up skills that they have already learned.
Later in the game, the ability to perform Carnage Unity on a Carnage that has already been created is unlocked. Doing so gives the Carnage a slight boost to its attack power and allows the Mirage to relearn and power up the skills associated with it, and to learn an additional fifth skill that was not available at the Carnage's base level. It does not require material components to reforge an existing Carnage, but on rare occasions, a Carnage the player selects to reforge may shine, indicating that Tiki can power it up even more by spending additional Performa.