Driscoll

Driscoll is one of the main villains and he appeared in Perfect Day and he appeared again in Ben 10 vs. the Negative 10: Part 1 and Part 2. He is also known as the Forever King.

Backstory
Driscoll was once a veteran Plumber who was kicked out of the Plumbers when it was discovered that he was stealing advanced technology from alien perps and using it for his own benefit. He later joined The Forever Knights and worked his way up the ranks to Forever King. He then created a splinter group with the desire to conquer the world and to gain revenge on the Plumbers.

Original Series
Driscoll was arguably called the main antagonist of the fourth and final season of the original series.

He appears at the end of Perfect Day, where he tells the Forever Knight Ninja not to release Enoch from the dream machine, saying he has failed him enough already and will deal with Ben Tennyson himself.

He soon creates a group of Ben's enemies, consisting of himself, the ninja, Dr. Animo, Charmcaster, Rojo, Clancy, Sublimino, and the Circus Freak Trio (Thumbskull, Frightwig, and Acid Breath). He planned to use them to destroy Ben and also targeted his cousin Gwen, his former Plumber grandfather Max, and their tag-along Cooper Daniels. When they escape most of their attempts, they hide out in the Plumber base in Mt. Rushmore, but Sublimino hypnotized Cooper to attack the Tennyson family.

After dealing with Cooper, the Tennyson family worked together and took down most of the Negative 10. However, Driscoll's real main motive was to take the Sub-Energy and use it to power up his suit to take over the world. However, Ben as Upchuck ate the Sub-Energy and defeated Driscoll he got away and avoided arrest.

Ultimate Alien
Driscoll returned in the Ben 10: Ultimate Alien episode The Purge, where he, among the rest of the Forever Knight faction leaders, were summoned by Old George. Although he initially attacked the old man, he stopped once he realised who he was and agreed to serve him.

Later, while leading a group of Forever Knights to capture aliens, he was challenged by Ben to honorable combat over the fate of the prisoners, which Ben, as Ultimate Spidermonkey, won. Despite this, Driscoll refused to let the aliens go, ordering the Forever Knights to kill them. However, after a powerful threat from Ben, Driscoll and his Knights withdrew. Driscoll apologized to Old George for his failure, and was surprised when George placed him in charge, while he went on a journey.

Powers and Abilities
Driscoll in the original series used a power suit that gave him enhanced strength, durability and could project energy blasts from his gloves. When he used the Sub Energy to enhance his powers, he could fire staggering energy blasts from his helmet's visor. However, the power suit was destroyed when Upchuck ate the Sub Energy and shoot it at him.

Trivia

 * Driscoll's helmet is similiar to the face of White Ranger (Trent) of Power Rangers Dino Thunder which is white in outer and red in inner.
 * When Driscoll appears in Ultimate Alien without his armor in the original series he haven't seem to age at all and he had been kicked out of the plumbers when Max was a rookie.