Deathroy has the appearance of a frog-like tiny creature, probably no bigger than 3 inches. His lower half is concealed by machinery, although this is actually merely used as a tether to Nene's shoulder. When released, Deathroy takes the full appearance of a Frog.
In the story, Deathroy is mainly Nene's sidekick with no active role until the end. After Nene was killed by Zola and the collar of light was used, Deathroy tells his true story and origins, and, having swallowed Nene's light sphere, enters his true form: Destroy. He seems to liquefy like a caterpillar in a cocoon with Szabo in the center. He says in a deeper voice how he feels his power returning.
After Destroy has fully transformed, cutscenes occur showing flashbacks of murals in areas like Pachess Town, Mural Town and the Talta ancient ruins. He says he was the most powerful biological weapon ever created, and the boss battle that ensues after proves this to be correct. He has incredible attacks, such as Final Judgment, which involves a massive thunder attack. Oddly, he seems to do less damage than Nene with the eternal engine, although he has a larger array of attacks.
Deathroy's role is the same in the anime minus the true last boss part. Following Nene's destruction, he partners with Delphinium and is revealed to be the true wielder of Chimera and grants Nene the ability to manipulate it since Deathroy cannot summon him by himself. Zola abducted Deathroy without anyone noticing and hid him in the Sealed Grounds. He was rescued by Delphinium and by using her artificial shadow Chimera becomes hers to manipulate with Deathroy, while still having her beetle/hydra shadow. Deathroy and Delphinium join in the final battle, with Chimera sealed after Zola in demon form is defeated.
Tenkai no Shichi RyuuEdit
Two years later, Deathroy continues to partner with Delphinium and regains Chimera by forcing Noi to after taking Bouquet hostage. When it came to fight with Hildegard, Deathroy directly uses his power to save Delphinium. He and Delphinium later help out in the final battle with Rudolph.