Joseph Chadwick

Dr. Joseph Chadwick was the director of alien technology for the Forever Knights and is current, and sole remaining Forever King. He continues his anti-alien activities and hopes to restore the Forever Knights to their former glory. He is currently an alien hybrid.

Personality
Chadwick has a sinister and psychotic personality. He has no qualms hurting aliens like Ship to achieve his goals. He is completely loyal the Forever Knights' cause. After becoming the new Forever King, his delusions of grandeur become more extensive and his fanatical ambitions have reached new heights. After drinking the Mr. Hyde Formula, he became extremely power-mad and somewhat insane.

Powers and Abilities
Before his transformation, Chadwick was a normal human being with some knowledge of alien technologies and chemicals. After drinking Dr. Jekyll's formula, he changes into a gorilla-like monster, (presumeably an alien gorilla) and gains enough strength to put him on an equal standing with Humungousaur with matching agility and ape-like dexterity. He has great endurance and stamina, able to survive an underwater cave-in.

Weaknesses
Chadwick's single-mindedness to eliminate all aliens from the Earth has already driven him to insane lengths. After drinking Dr. Jekyll's formula, he had become even more unstable, choosing to remain inside a flooding chamber and preventing anyone from leaving.

Ben 10: Alien Force
In his debut episode, Pet Project, Joseph was assigned to oversee the mass-production of an Anterian Obliterator spacecraft that would enable the Forever Knights to travel to the alien dragon's planet after Ben helped it escape in Be-Knighted. But because the technology was too complex for human operation, Joseph sent Sir Morton to capture Ship to help perfect it. During the confrontation at his hideout, Joseph used a control device on Ship. That plan proved to be a failure later during the episode when Julie Yamamoto helped Ship gain control of himself again. When Swampfire threw a fireball at a gas tank inside the hideout, it exploded and caused a collapse in the hideout. While Sir Morton and his gang escaped, Joseph was caught in the cave-in but managed to survive.

Ben 10: Omniverse
Joseph reappeared as the new Forever King in Return to Forever, where he tried to wipe out all alien life with a Highbreed Pulse Generator, but was stopped by Ben and knocked out by Jimmy Jones.

In An American Benwolf in London he transforms into a gorilla-like monster after drinking Dr. Jekyll's formula so he could pull Excalibur from the stone. He proved to be unsuccessful despite his increased strength, and was last seen escaping from the Thames River with the damaged Forever Ninja. Seeing that he could not claim Excalibur for himself, he left it behind in its underwater vault.

Ben 10: Alien Force

 * Pet Project (first appearance)

Ben 10: Omniverse

 * Return to Forever (first re-appearance)
 * An American Benwolf in London

Trivia

 * Joseph's sinister and psychotic tendencies towards Ship and experimenting aliens for combat use are similar to the real-life Dr. Joseph Mengele (he and Chadwick even share the same first name), a WWII criminal also known as the "Angel of Death", while his status as weapons technician for a paramilitary group was inspired by Wernher von Braun, creator of the deadly V-2 combat rocket technology during WWII.
 * Ironically, Joseph is now a human/alien hybrid, despite the Forever Knights' fanatical anti-alien stance.