Evil Emperor Guylos

A right bastard, Evil Emperor Guylos was not particularly creative with his titles (though the "evil" seems to have been more a Tomy thing), but lived up to his reputation.

He ruled ruthlessly over Nyx for quite some time, presumably having taken over for the Guylos King Helic fought back when, and was known for being particularly brutal in his strategies (and impatient with people not smiting things fast enough for him, going by Störmer's experiences in Tomy's take on things).

Especially of note is his relationship with Zenebas. He allied with the ruler the first time he started losing to his brother, letting him stay on Nyx and build up an army of doomy Zoids. The second time Zenebas was in trouble, Guylos showed his true intent, and absorbed Zenebas' remaining army by force—and kidnapping. Zenebas and his daughter Elena were reduced to useful hostages until the meteor disaster.

Zenebas died then, and Guylos seems to not have been around much longer either. Elena, on the other hand, went on to become the Republic's new president. So there.

Continuity

In Tomy's Zoids Graphics take on things, Guylos killed Zenebas and kidnapped Elena. In Shogakukan's original one, Elena didn't exist and he kidnapped just Zenebas. The new stories apply a bit of retcon to have them both be kidnapped together.

Tomy's catalogue/Graphics art has Guylos as having claws. Long, fairly reptilian claws.