Deboth

Deboth is the leader of the Deboth Army and the main antagonist of Zyuden Sentai Kyoryuger. Referred to as the "Planetary Illness", Deboth travels the cosmos destroying various lifeforms.

Initially appearing in his "Dark Species" form which he used to wipe out the dinosaurs in Earth's past, Deboth later evolves into his "Transcendenterfly God" form to wipe out the humans.

Past
Deboth was originally created by Creator Devius for the purpose of becoming the ultimate lifeform.

Traveling the universe to destroy various life forms, Deboth created Chaos and Torin as his heralds and sent the latter to Earth during the Mesozoic Era. However, Torin betrayed Deboth and assembled the Zyudenryu to face him when he came to Earth personally. During the fight, Deboth destroyed all 13 Guardians Zyudenryu alongside his creation Gadoma. However, both were critically wounded by an enraged Bragigas soon after using the forbidden Gigant Cannon. With his heart damaged and cells scattered across the planet, Deboth's body entered a dormant state, allowing Torin to seal it away in the Antarctic seabed, where it became the Frozen Castle and base for the Deboth Army.

Return
With Deboth sealed, his High Priest Chaos assumed leadership of the army and began working to thaw him out by collecting human emotion with assistance from his Knights Candelilla and Aigaron. Eventually, Deboth was awakened when Chaos flooded a dam filled with Restoration Water, releasing him in his Dark Species form which he had used in the prehistoric age to destroy the dinosaurs.

At first, Deboth was just a mindless beast due to Chaos not having enough Joy and Anger emotion energy to fully thaw out his heart. Despite this Deboth easily overpowered the Kyoryugers until Daigo's fighting spirit pushed him back and caused him to panic. He eventually turned his attention to his own army thanks to Luckyuro's shouting, so Chaos had Luckyuro shrink him down to human size. Deboth was later resized back to a giant again to finish the job of destroying Plezuonb.

He was soon faced again by the Kyoryugers and the only Zyudenryu still fit for battle (Gabutyra, Plezuon, and Bunpachy). The Kyoryugers soon formed Bakuretsu Kyoryuzin and managed to obtain the advantage over him thanks to the Deboth Cell Destruction Program that was installed in Plezuon. Chaos tried to get Deboth to retreat but was unable to and so as a result Deboth was destroyed by Bakuretsu Kyoryuzin's finisher.

Despite Deboth's destruction, the Frozen Castle somehow managed to stay preserved. It would later be revealed that Deboth had survived by transferring his heart into Chaos before he was destroyed, allowing the Castle to be restored.

Final Form and Endgame
After learning joy and sorrow, Deboth evolved into his final form as Transcendenterfly God Deboth leading the Deboth Army. He began a countdown of 50 hours until he destroys the Earth. The Kyoryugers thus entered into their final battle with the Deboth Army to save the Earth. Daigo led the final assault on the Frozen Castle and soon came face to face with Deboth, who revealed that he was designed by creator to become the ultimate lifeform. Deboth proceeded to beat Kyoryu Red down but before he could finish him off Daigo was heard by his friends singing the melody of Earth. Empowered by the melody, Daigo became Kyoryu Red Carnival and finally destroyed the dark god by firing the Zyudenryu at him.

Zyuohger
A recreation of Transcendenterfly God Deboth was later summoned by Bangray alongside a team of recreations of other past foes of the Super Sentai. While Gokai Red and Zyuoh Eagle fought together, the Deboth recreation battled the remaining five Zyuohgers alongside the recreation of Brajira of the Messiah. Both Deboth and Brajira were defeated by their combined Zyuoh Slash.