Unidoom is a Phantom Beast Warrior who holds the spirit of the Unicorn. Unidoom wields wrist-mounted blades that emit Rinzin Power. After the Shark Spirit Ranger was defeated by the Claw Cannon, Scorch had Unidoom dispose of the Crystal Eye that Master Finn is imprisoned in, but Flit rescued it at the last moment. Following Master Finn being freed and then the freeing of the other masters, R.J. joins the Rangers in the fight against Unidoom who is accompanied by Camille and the Rinshis. He was defeated by the Spirit Rangers. He was revived in Now the Final Fury for the final battle, but was defeated along with Grinder by Theo.