[4] At times he can be a more restrained leader, particularly when Lotor does something rash, Zarkon will calmly handle the situation and chastise his son in private.
King Zarkon became an ally of the Voltron force against Prince Lotor as a member of the Galactic council.
Zarkon became corrupted by Quintessence and unknown dark forces from an alternate reality which led to a revolt against King Alfor to claim Voltron for himself.
[6] During flashbacks of Voltron: Legendary Defender, Zarkon is voiced by Kevin Durand instead of Neil Kaplan.
Voltron writers said the reason a different voice actor was chosen to show how Zarkon is not the original person he once was.