The Amalgam (アマルガム, Amarugamu?) is a form for the Symphogears introduced in Senki Zesshō Symphogear XV, unlocked by accessing the hidden power of the Symphogears rebuilt by the Philosopher's Stone during the battle with Adam Weishaupt. It is a fusion of the Symphogear and a Faust Robe.
Amalgam comes from the structural similarities between the Symphogears and the Faust Robes that results in the mixing and fusion of their formation energies. Upon activation, it instantly releases the energy that composes the Symphogear and reforms it into a golden "Cocoon", a first stage that gives the user a far more powerful barrier field (and that consumes far more energy) than normal. Next, the energy is reformed into a high-output armed gear, becoming a reorganized into an "Imago" that serves as a second stage.
Put simply, it causes an extreme imbalance between defensive and offensive parameters. In the Cocoon stage, defensive ability is greatly raised while attack power is greatly hampered. In the Imago" stage, attack power is greatly raised while defensive power is greatly hampered. As a result, the number of situations where this ability is useful is limited.
Despite its apparent lack of flexibility, for the Symphogear users who have been practicing and training with many of the Symphogear's special functions (starting with G3FA), it is seen not as a new restraint but is hoped to become a potential alternative to the power offered by the destroyed Ignite Module.
While in the Imago stage, Hibiki forms two large golden fists connected to her shoulders that she controls with her arms. They are able to detach and fly independently, and spin rapidly to become a drill. The spirit of Saint-German floated behind Hibiki while she was in this stage, singing a duet with her.Tsubasa's Imago stage forms a large golden sword, which opens up and unfolds into a blade resembling the Seven-Branched Sword. The branches of the sword all spin around to the same side of the blade, making it resemble a wing, before the entire weapon is engulfed in a massive blue flame.
- Faust Robe — An alchemic armor transmuted via an energy source such as the Philosopher's Stone or a relic.
- Ignite Module — The form harnessing the Berserk mechanic, accessed through Dáinsleif to massively increase the gears power.
- X-Drive — Another power-up that is even more powerful, but is considered a miracle due to how much phonic gain is needed to unlock it.