by Van in another battle. It is replaced by a prototype Genosaurer, which later evolves into the powerful Geno Breaker. Admiral Gunther Prozen - Gunther is the main villain of the series. He is the Regent of the Guylos Empire, an Admiral in the Guylos military, and the second in line for the throne of Guylos. Prozen arranges for Prince Rudolph, next in line for the throne, to be kidnapped and assassinated so that he can seize power after Emperor Zeppelin's suspicious death. He plans to use the Death Saurer to take total control of the world. He is believed to be killed after his Death Saurer is destroyed, but is shown to have survived as the Dark Kaiser. Hiltz - Hiltz is an Ancient Zoidian with a red Organoid named Ambient. His driving goal is to restore Zoidians to power, even if all humans have to die to do so. He pilots the Death Stinger and later merges with the Ultimate Death Saurer. Hiltz is the main antagonist of Zoids Guardian Force, and arguably the entire series as his arc is tied to Fiona's past and the quest for the Zoid Eve. He is killed in the final episode when Van is fired through the gravity cannon and penetrates the Ultimate Death Saurer. Rease - Rease is an Ancient Zoidian with a blue Organoid named Specula. She pilots a Double Sworder, and later upgrades to an advanced "Psycho" Genosaurer which was developed based on the data of Raven's Geno Breaker. She and her Organoid both possess psychic abilities, and she often uses psychological warfare and mind-control to disable her enemies. While she is first an ally of Hiltz, she changes sides after she finds out Hiltz had been using her all along. She appears to have some feelings for Raven, as she does help him come to terms with his past. Dr. D - Dr. D. is a self-confessed mad scientist once employed by the Republican Army as a Zoid researcher. He is considered Zi's foremost expert on anything Zoid or Organoid related, and enjoys hanging around with Van and his group. His attitude and demeanor irritates Van and Irvine, but D.'s knowledge comes in handy on several occasions. Prince Rudolph Zeppelin III - Rudolph is the grandchild of Emperor William Zeppelin. Rudolph is placed into the care of Van by Rosso and Viola, former waste gangsters turned bodyguards.