During Siegzeon's resurrection and attack, Summoner Roux risked her life to summon the Roux Dragon, which once again gathered the souls of Gunrex that had spread throughout the Suda Doaka World and materialized them. It has more power than the former True Holy Machine Soldier, and was able to stop the moon from falling.
It appeared in the final battle in response to Superior Dragon SR. It was piloted without a pilot, and fought in response to the feelings of those who loved Suda Doaka World. After the battle with the Armored God, it is said to have slept deep within the Valley of the Kings, which could be called its home, and during that time it seems to have evolved into a new form.