Subtitle: Nature Control Machine (自然コントロールマシーン Shizen Kontorōru Mashīn)
- Height: 48 m
- Weight: 84,000 t
- Origin: Space
Created by unknown beings, Tenkai, along with Enzan and Shinryoku were made to repopulate Earth with new specimens when one species "overevolves". Tenkai was the first of the three to be activated, unleashing a tornado and slowly sweeping towards Japan. However, one of its pieces flew into a building and was examined by XIG, thus revealing its existence. Tenkai was then assaulted by Team Lightning and hurried to Japan's shores and attached itself to its base, and began ramming at the fighters repeatively. Ultraman Gaia soon appeared and the two clashed. Unfortunately, Gaia could not hold on to Tenkai for very long due to its rotation, and soon Tenkai began to hammer Gaia with tornadoes and hurricane. The hero seemingly disappeared, but not for long. As Tenkai rose up, Gaia burst through the ground and drilled a hole in the center of Tenkai's body, emerging through the top with Tenkai's main control system. Gaia throw the core back at Tenkai, which then exploded.
- Powers and Weapons
- Weather Control: Tenkai can control the atmosphere at its please.
- Tornado: Tenkai can summon a tornado to begin the cleansing process.
- Hurricane: Tenkai can summon hurricanes to protect itself.
- Gas: Tenkai unleashes a gust of gas.
- Rotation: Tenkai's base can rotate so that it is impossible to touch
- Flight: Since its purpose was to cleanse the atmosphere, Tenkai can fly very well.
- Base: Tenkai owns a base underground that it can attach to in case for combat.