Forever King Driscoll
The first Forever King featured in the original series was the fourth season's main antagonist. This Forever King was originally a former Plumber named Driscoll. However, he was thrown out of the Plumbers organization in disgrace when he was revealed to have been stealing alien tech only for his own benefit. He later joined the Forever Knights and worked his way up through the ranks, eventually forming a splinter group of knights with the desire to conquer the world and get revenge on the Plumbers.
Driscoll first appeared in Perfect Day where he finds Enoch trapped in a dream world. He leaves Enoch to his fate after his multiple failures and says he will take care of Ben himself. He appears again in Ben 10 vs. the Negative 10 where he rounds up a collection of Ben's old enemies to form a specialized team, in an effort to steal the Sub-Energy, the most powerful energy source on Earth and given to the Plumbers after capturing an alien convict. Driscoll eventually manages to steal it and enhances his powersuit with it, but the energy source is eaten by Perk Upchuck. His suit is destroyed, but Driscoll survives and escapes.
Forever King Patrick
The Forever King of Alien Force, he first appeared in the episode Be-Knighted, giving an alien weapon to Connor that was believed to be powerful enough to slay the captive Alien Dragon, around which the entire Forever Knights Organization had been formed. Upon the failure of Connor to slay the dragon, he countered Connor's claims that the Forever Knights were un-needed by stating that the world now needed them more than ever, as they now knew that there was an entire planet of dragons who may be plotting revenge.
Forever King Urian
The Forever King Urian, is another Forever King, of another faction of The Forever Knights that tries to get the ancient Mexican toltech battle armour. Urian appeared in Duped, with the ability to shoot electricity out of his hand which is confirmed by Dwayne McDuffie to simply be a gun inside his armor.
Forever King Chadwick
Joseph Chadwick, once the director of alien technology for the Knights, has since become the new Forever King, ruling over the small remains of the once massive group. His men are comprised of two knights in twin armor and masks, one happy faced, and one sad faced, his old ally and henchman Sir Morton, and the rebuilt Forever Ninja robot. His technological mastery has equipped his men with advanced armor and weapons that increase their speed, strength, and combat abilities.
With ample funding from Will Harangue, whom Chadwick promised to help rebuild his ratings and viewership, Chadwick planned to use a DNA Scanner to scan all the aliens in Undertown. This DNA would then be used in a Highbreed Pulse Generator, to erase all alien DNA on Earth (Chadwick lied to Harangue, saying it would rewrite the aliens genetic codes and turn them into humans). Ben and Rook stopped this plan and instead used the device to turn Harangue into an alien as a form of retaliation by Ben.
Chadwick later reappears in London in An American Benwolf in London, seeking the legendary sword Excalibur. Using one of Dr. Jekyll's formulas, he transformed into an alien gorilla-like monster in order to pull out the sword from its stone, but he failed in the attempt. After a short battle with Ben and his comrades, he was last seen escaping from the Thames River, still in his mutated form, and carrying the damaged Forever Ninja.
- They are similar to Adolf Hitler, a real-life leader of a notorious political party and paramilitary group during the 1930s and '40s, who promised to have his party to lead his country to success, but then skewed it into a criminal system.