Nada

Nada is a member of the Ryusoul Tribe who is later revealed to be the current wielder of the Gaisorg armor and a major antagonist in Kishiryu Sentai Ryusoulger.

He is a mysterious Ryusoul tribesman who in the past also trained under Koh's mentor Master Red before leaving to wander the Earth after he was unable to become a Ryusoulger.

History
He originally trained under Master Red and sought to become leader of the Ryusoulgers. However, his desire for power was what ultimately caused him to be rejected from becoming a Ryusoulger and thus, Nada left to wander the world.

At some point, Nada recovered the Gaisorg armor after Rita was forced out of it by Towa and Bamba and became its new wearer.

As Gaisorg, Nada at first seemingly assisted the Druidon Tribe in their fight against the Ryusoulgers. He assaulte the Ryusoulgers several times, only to abruptly leave without finishing them off. Nada later approached Canalo in his civilian identity and requested that he take him to see the other Ryusoulgers. Meeting with them, Nada claimed that he wanted to assist them in their fight against the Druidon Tribe.

Nada later trained Koh to use the Smash Soul to destroy the Beelzebub Minosaur that had its tail wrapped around Asuna's heart, using a water balloon with a net around it and telling him to only destroy the net. However, after Koh failed repeatedly, Nada gave up on him.

After hearing that Canalo's current girlfriend didn't want him to do anything dangerous, Nada approached him and advised him to stop being a Ryusoulger. Later, as Gaisorg, Nada attacked Towa and Bamba. His true identity was finally revealed when they knocked Gaisorg's helmet off of his head. Nada simply complimented them before beating them back and exiting.