Robofusion

Robofusion is a special ability that can allow the Tenkai Knights or the Corrupted to combine each with other into giant war machines that are more powerful than their singular forms.

Prodojet
The Prodojet Tenkai Knights' first Robofusion that resembles a giant battleship, armed with pieces and colors from Bravenwolf and Tributon. It's special technique is the Phoenix Attack.

Air Lancer Jet
The Air Lancer Jet is the second Robofusion that the Tenkai Knights have achieved. It is armed with the color of Valorn and Lydendor. It's special technique is the Tenkai Thunder Cannon.

Xenoship
The Xenoship is Vilius's Robofusion with three of his soldiers.

Sickle Ship
The Sickle Ship is Granox & Slyger's Robofusion with a Corrupted soldier and a Sho. It's special technique is the Dark Raven Attack and can also move while underground.

Titan Fusion
Titan Fusion occurs when two menbers of the Tenkai Knights robofuse while in Titan Mode.

Slyger and Granox appear to perform a variant of Titan Fusion, although they robofuse with a mech beast (a Sky Griffin and War Stallion, respectively) and only when they have been empowered with energy from the Tenkai Dragon.

Trivia

 * The Xenoship and the Prodojet are both able to be made by connecting four different toys each. (Prodojet - Tributon, Kutor, Leinad, and Bravenwolf and Xenoship - Vilius , Rho, a Hos, and a Sho)
 * All current Tenkai Knight Titan Fusions incorporate Bravenwolf, but only one has him as the upper body.