Gaia is the strongest Sacred Mechalord created by the Ancient Civilization and the being responsible for its downfall and acts as the true antagonist of Tenchi Muyo War On Geminar.
Ancient and powerful humanoid constructs that were built by an ancient race called the Senshi. Gaia is the only surviving Sacred Mechalord and was unearthed intact (although immobile) by the Shtrayu Empire, and was mainly used as a decoration before the arrival of Kenshi triggered a response from it. It was revealed that the Senshi civilization was completely destroyed by Gaia. and later on its revealed that Babalun's father put Gaia's Core Crystal in his body when he was young and later on Gaia has been revived with Doll inside of it.
Kenshi faces off against Doll and to everyone's astonishment, Kenshi is fighting on par with Doll. The tables are later turned when Babalun with merges with Gaia and begins to overpower him. Kenshi decides to go all out while Gaia continues to regenerate. He later hears Doll/Mexiah asking him to save her from Babalun/Gaia.
In the midst of the battle, Kenshi goes berserk and generates a Light Hawk sword, causing him to destroy the main core of Gaia and save Doll/Mexiah, who both have fallen in love with Kenshi. Babalun later emerges from the scraps, vowing to kill Kenshi, but Ulyte intervenes and kills Babalun, at which point he collapses and reveals his true identity as Rea Second.
At the end of the story, it is hinted that Dagmyer become infected by Gaia's core jewel.