Carl Nesmith

Captain Nemesis, later known as Overlord, is a character introduced in Ben 10: Ultimate Alien episode, Hero Time. Originally a famous human super-hero known aswell as a great American icon, as well as Ben's idol, but later became a greedy gloryhound and a fraud. After a jealous rivalry with Ben as a hero however, Nemesis eventually went insane with jealousy and became the villain named Overlord. He is voiced by Christopher McDonald.

Ultimate Alien
Captain Nemesis was introduced in Hero Time, though it was made obvious that he had been active as a vigilante since a long time (before Ben were ever born according to him). A famous super-hero and a great American icon according to most characters, his long services as a vigilante made him rich and famous, having his own weapon-making company and comic book series. In reality, he's really a greedy glory hound fraud who stages all criminal activities he seemingly stopped in order to get fame and fortune, though his agent implied he has been a true hero in the past. Unlike Ben, he is shown to be greatly estimated by the anchorman Will Harangue, who described him as a "true American hero", a patriot.

In his first appearance, Captain Nemesis organizes a faked kidnapping on young movie star Jennifer Nocturne in order to save her and come back on the first page of the news. However, the faked kidnapping was mostly stopped by Ben before he arrived, causing Ben to get most of the credit. This, plus Jennifer kissing Ben in front of the media, caused Captain Nemesis to grew jealous against Ben, despite the boy's admiration for him. After a second attempt to get back credit was once again unwillingly spoiled by Ben, the older hero proposed a "friendly competition" between the two of them to see who was the best. Though he was able to win one test thanks to an Ultimatrix's disfunctionment, he ended up being humiliated by Ben as Fourarms, definitely ruining his image.

After his defeat against Ben, Captain Nemesis turned insanely rancorous toward the younger hero, and upgraded his armor in a dangerous way in order to get revenge on him. He then kidnapped both Jennifer Nocturne and Julie Yamamoto, using them to bring Ben and fight him again. After a brief fight with a rampaging Ultimate Humongousaur, he put both girls in danger, intending to force Ben to choose which one save. Ben eventually saved Julie as Goop, while Gwen and Kevin took care of saving Jennifer. During the fight, Captain Nemesis expressed a disgust and disillusionment for having "wasted" his life saving pathetic souls like Ben, and renamed himself, Overlord, stating that Captain Nemesis is dead. Ben was then eventually able to defeat the former hero by cooling down his overcharged armor as Water Hazard. He is then taken into police custody.

Ben 10 Ultimate Alien: Cosmic Destruction
Overlord appear in the new game Ben 10 Ultimate Alien: Cosmic Destruction, is unknown when him appear in the game. More info coming soon.

Powers and abilities
Captain Nemesis had no powers by himself, instead relying on a powered armor to fight crimes. The armor basically gave him superhuman strength and enhanced durability, along with a grappling hook that allowed him to swing across buildings. Various other equipment could be added, such as boosters to make him faster. However, the armor was so complex that he needed an entire staff of technicians to help him put it on.

After his upgrade as "Overlord" in which he boosted the core, he displayed much greater strength, speed and durability, as well as new powers such as flying and projecting energy from his hands. However, as a side effect, the armor grew hotter each time he used it, and, according to Kevin, would have blown up and destroyed him if Ben hadn't stopped it.

Trivia

 * The fact that he is wearing a cybernetic suit and was a famous hero at the same time a rich industrialist is a reference to Iron Man of Marvel comics fame. Even his face also looked exactly like Tony Stark.
 * He has a strong resemblance to Adonis from Teen Titans.
 * It is possible that he will return in his Overlord alias with a new suit that won't have his original armor's side effect.
 * Overlord is the third villain to change his name. The first is Michael Morningstar who changes his name to "Darkstar" in Darkstar Rising and the second is Dr. Animo who changes his name to "D'Void" in Voided.
 * He is voiced by Christopher McDonald, and the character is apparently a pastiche of McDonald's previous corrupt antagonist characters who were all a force for good that have gone over the edge:
 * 1) The brainwashed Superman from Batman Beyond (a long-time known superhero finally turned villain upon being controlled by Starro)
 * 2) The paranoid CIA agent Kent Mansley from The Iron Giant (an ally of the U.S. who views the protagonist as a threat)
 * 3) The jealous Dr. Wilson Croft from Flubber (the protagonist's equal counterpart who is jealous of the protagonist gaining all the attention)