Forever King George
Sir George was the first Forever Knight and founded the organization over 1000 years ago. In The Purge, he recruits the other Forever Kings and unites all of the Forever Knights factions into a single order and then started a war against all aliens on Earth. In The Ultimate Enemy: Part 2, George takes a direct lightning attack from Diagon and tries to defend himself with Ascalon, which backfired since Ascalon conducted the lightning into George, turning him back into an old man and electrifying him until he crumbles to dust.
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. According to Derrick J. Wyatt, Driscoll, like all of the other Forever Kings, is somehow dead.
Forever King Patrick
The Forever King of Alien Force who first appeared in the episode Be-Knighted, when he gave 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 Connor's failure to slay the dragon, he countered Connor's claims that the Forever Knights were unneeded 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 armor. 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. According to Derrick J. Wyatt, Urian, like most of the Forever Knights, is somehow dead.
Forever King Cyrus
Sir Cyrus is the leader of a faction that he claims is the true path from the ones led by Driscoll, Patrick, Urian, and Enoch as he follows the ways of the First Knight Sir George. In A Knight to Remember, Cyrus and Driscoll rally with George to find his sword, Ascalon, but when Vilgax gets the sword and absorbs Diagon's heart, he takes them all out. Later, when Cyrus and George confront Vilgax at the seal that the Lucubra emerged from, Vilgax kills Cyrus and takes out George.
Forever King Enoch
In The Purge, Enoch is shown to be the leader of his own faction of Forever Knights when he attends a meeting of fellow Forever Kings, Driscoll, Patrick, and Urian until Old George arrives and berates them for separating the Forever Knights and then reveals his identity to them, causing them to kneel before them. Old George then unites the Forever Knights factions. According to Derrick J. Wyatt, Enoch didn't appear in Omniverse because he's somehow dead.
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.
- Joseph Chadwick is the first Forever King to become an alien hybrid.
- According to Derrick J. Wyatt, all of the Forever Knights, including George, Driscoll, Enoch, Patrick, Urian, and Cyrus all died before Omniverse except for Forever King Chadwick and Sir Morton.