It is later revealed that Azald is actually Azald Legacy, an immensely powerful alien who once terrorized Zyuland long ago until he was repelled by the Zyuman Cetus with the power of Zyuoh Whale.
In the distant past, Azald Legacy attacked the Zyumans and threatened the planet. The only one willing to oppose Azald was a young whale Zyuman named Cetus whom Azald Legacy easily overpowered. However, the planet responded to Cetus's desire to protect all life and bestowed him the power of Zyuoh Whale. With his newfound powers as the original Zyuohger, Cetus used the Whale Change Gun to freeze Azald and send him into space via Cube Whale.
Hearing rumors of a monster that had been tossed into space from Earth, Ginis began searching for Azald and eventually discovered his body floating in space. Ginis attempted to remove the seal Cetus had placed on him, but this had the unintended result of causing a crystallized structure to form around Azald's body. With no memories of who he was, Azald joined the Deathgalien and swore loyalty to Ginis.
As a Deathgalien
Azald later showed up to Earth aboard the Sagittari Ark along with the rest of the Deathgaliens for the 100th round of their blood game. He was first seen playing a board game with fellow Team Leaders Jagged and Quval, only for Jagged to eagerly pull away from the game once they arrived at their destination.
Following Quval's betrayal and death, Azald did not feel the need to continue the Blood Game, as he had no more competition, but Ginis told Azald that Quval could still win posthumously for his attempt of trying to overthrow him. Wanting to win, Azald sent another one of his Players to Earth, as well as participated himself to try to further amuse Ginis. During this attempt, Azald fought Yamato and Misao, with Yamato summoning Cube Whale. Recognizing Azald as its ancient nemesis, Cube Whale immediately attacks the Team Leader, prompting Azald to flee.
Becoming Azald Legacy Again
Azald later broke free from his body's cubic crystallization, regaining his memories as Azald Legacy and reassuming his original form. He later returned to the Sagittari Ark and demanded Ginis tell him what he had done to him. Ginis told Azald how he had recovered him and stated that Azald should be grateful that Ginis puled him out from space. Adding on to that, Ginis told Azald that now that he had regained his full power, he expected more entertainment from him. However, Azald announced that he and Ginis were now equals, and that the Blood Game would now be between them to see who could cause the most destruction.
Azald Legacy then resumed his rampage on Earth, coming into confrontation with the Zyuohgers once again. Though initially overpowering the Zyuohgers, the team eventually succeed in exposing his core. However, before they can do anything, Naria infused the core with three Continue Medals, causing Azald Legacy to enlarge and lose control. Angry at Ginis for using him, Azald Legacy goes on a highly destructive rampage before his body was destroyed by Zyuoh Dodeka Dynamite Stream, exposing his core once again. The Zyuohgers then freeze it with Whale Charge Gun to prevent Azald Legacy from regenerating before finishing him off.
- Azald's massive strength as well as his ability to regenerate brings to mind about Mr. J from 2003 TV series called Kamen Rider 555.
- Him having a past with the non-human heroes' homeworld makes him very similar to Brajira of the Messiah from 2010 TV series called Tensou Sentai Goseiger.
- In his ultimate form Azald is very similar to Ultimate Org Senki from 2001 TV series called Hyakujuu Sentai Gaoranger.