Who are Zeta's humans?

Zeta Altman, a disciple of Zyro Altman, is as enthusiastic as Zyro and a very positive Otto hero. Moreover, Zeta worships his master Ciro very much. Although Ciro refused to admit this apprentice, he was still very optimistic about Zeta. The human related to Zeta Altman this time is a warm-blooded young man named Xia Chuan Yao Hui. Yao Hui is a member of the monster's "armory" against the mecha. A long time ago, for some reason, something called devil fragments appeared in the universe, which could make monsters lose their minds. A mysterious guy is using these demon fragments to harm all directions and extend his claws to the country of light. Ciro and his apprentice Zeta took the initiative to attack the enemy in order to defend their homeland. After a fierce battle, Zeta was forced to separate from Ciro and chase the escaped monster alone. When Zeta reached the earth, she met Yao Hui who was fighting.