|Anime Debut||Episode 1|
|Seiyu||Koji Yusa (Japanese)|
Keith Silverstein (English)
Seiji Haitani is the brains of EVOL, and is considered the first major antagonist of the series.
He seems to have an interest in Jin Kanzaki, as he implanted a ceramic spike into Jin's heart in order to allow him to freely become ZET. He is shown to be merciless when it comes to geting what he wants, going as far as to fake the decapitating of Akemi Kawakami's son in an attempt to get Jin to give him Kanzaki's pendant. While Jin and Kouga Amagi are on their respective dates, Seiji delivers a declaration of war to the human race. After wards, as he threatens to destroy EVOL if Jin is killed, Seed beheads and attaches the leader's head to itself, and they proceed to presumably kill Seiji. He survives, and soon meets up with Suzuki, the person Youko is staying with. He then delivers a message to Jin, telling him to join forces with him to defeat EVOL, also revealing to him that the Amagi Corp. was funding EVOL and that the black suits were in on it, though that part was a lie. He then launches an attack on Amagi Corp. along with Hayami, the Knight Player, and Suzuki ("Katou"). During the attack, it is revealed that he is holding Hanako hostage, as a means of making Jin do what he wants.
Third-generation player, is the brain of EVOL. Haitani is a difficult character to understand, tricky, fake, cold, while reserving for Zetman some confidence in its potential, it is possible that, from time to time, deems it unnecessary to its purposes. Not afraid to let the world know the existence of EVOL and uses any means necessary to achieve its purpose.