Kamishiro Genji (上代源治) Voiced by Shinichiro Miki. The series' main antagonist.
The commander of Custos. Not much is said about his background. Claims that the capture and killing of Larvae is for the sake of order. However, Kamishiro is actually a Larva who can take the powers of others as his own before he decided to abuse his power for world domination. In Chapter 6, he absorbed a portion of Towa's powers and tried to turn all the humans in the facility into Larvae. He was defeated by Quon when Towa overloaded Quon's powers and lost all of his abilities because of it.
A cold-hearted man and power hungry, it is shown that he does not have much care for his subordinates and, valuing results and his own agenda above all.
A middle aged looking man of average height with white hair. He is always seen in his black suit. In the final episode he looks almost like a mummy and acts hysterical.
- He is voiced by Andrew Love in the English version of the films.