Vulkanus

Vulkanus is a Detrovite who partnered up with Sixsix in order to build a weapon capable of destroying a solar system using element X.

Ben 10
In the original series, he is almost always seen with Sixsix. He is stopped by Ben and the Galactic Enforcers in the episode, The Galactic Enforcers.

He reappearsin Ben's dream world in Perfect Day working alongside Sixsix again.

In the start of the future episode Ken 10, where he was defeated by Ben 10,000 and was transported to the Null Void.

Ben 10: Alien Force
Vulkanus makes a brief appearance in Ben 10: Alien Force in the episode Kevin's Big Score. From this appearance on, he now has a chrome-purple suit. According to himself, he was betrayed by Kevin during a "counterfeit isotope" scam a few years earlier. Kevin left him holding the merchandise when The Plumbers arrived, and though he managed to escape, the Plumbers destroyed his ship. Unable to leave Earth, he resorted to trading level three alien technology to get by. When Kevin arrives looking to obtain an important item(a holo-viewer from Grandpa Max), Vulkanus decides to get back at him for the betrayal by forcing Kevin to absorb a small piece of Taedenite, the rarest living gem in the galaxy. This causes Kevin's body to mass-produce the gem, thus giving Vulkanus an endless supply. However, he is foiled by Ben, who uses Big Chill to literally freeze off his armor, revealing that Vulkanus is really nothing more than a minuscule alien in a giant suit. Rather than attempt to arrest him, however, Kevin leaves Vulkanus with the small fortune in crystals he had managed to chip off beforehand, considering it as payment for his past actions.

He reappears in Inferno where he plans to detonate a bomb which will raise the Earth's temperature to 800 degrees. The bomb is stopped by Ben and Kevin is happy that Vulkanus wasted his money.

He makes a brief appearance in Con of Rath. When Ben (as Rath), Gwen, Kevin discover they need Taedenite to power their ship, Gwen tells Kevin that every time they come across Taedenite they run into Vulkanus. Kevin says their imagining things only to be confronted by Vulkanus. Kevin tries to negotiate with Vulkanus using a gold credit cube(an alien form of currency with no spending limit) but Vulkanus holds firm. He is defeated by Rath who ruined most of his Taedenite. Beaten Vulkanus is forced to hand over his remaining Taedenite.

Ben 10: Ultimate Alien
Vulkanus also appears as one of the villains after Ben in Hit 'Em Where They Live, teaming up with Zombozo and Charmcaster and is beaten at the end by Ben as Ultimate Big Chill.

Vulkanus was suddenly afraid of Ultimate Big Chill after witnessing the effect with his "ice flames" He appeared again in Absolute Power being beat up by Humungousaur because he wanted answers about where Kevin was.

Ben 10 Ultimate Alien: Cosmic Destruction
Vulkanus appears in Ben 10 Ultimate Alien: Cosmic Destruction. His role in the game is that of a minor antagonist. He is the mini-boss of the Catacombs level.

Ben 10

 * The Galactic Enforcers (first appearance)
 * Perfect Day
 * Ken 10

Ben 10: Alien Force

 * Kevin's Big Score
 * Inferno
 * Con of Rath

Ben 10: Ultimate Alien

 * Hit 'Em Where They Live
 * Absolute Power: Part 1
 * Greetings From Techadon

Video Game

 * Ben 10: Protector of Earth
 * Ben 10 Ultimate Alien: Cosmic Destruction

Trivia

 * Vulkanus has been beaten by a Big Chill two times, once by normal Big Chill, and again by Ultimate Big Chill.
 * Vulkanus's His name probably derives from "volcanic", due to his heat resistant abilties, and the name of his home planet, Vulcan, which, in itself, is named after the Roman god of smithery of the same name.
 * In the original series, Vulkanus seemed to be at the same build as Technorg minus the mace hand, but from Alien Force onward, he is shown to have a infant-like body. Dwayne McDuffie has confirmed that he was this size the whole time his suit and Technorg's suits were merely colored in mimic flesh.
 * In Absolute Power part 1, Vulkanus revealed that whenever his suit gets either damaged or destroyed; the arms are the hardest to repair because "They're always on back-order".
 * Vulkanus is one of the few villains to appear more times in Alien Force/Ultimate Alien than the original series.
 * Vulkanus is one of the few villains that has only been encountered once in the original series, (Perfect Day and Ken 10 do not count as he was a dream in Perfect Day and Ken 10 is in an alternate timeline)
 * Vulkanus's the 1st villian from original series, who apper in Alien Force (without Kevin, who was become good).In Kevin's big score
 * In Kevin's big score, his suit was a greenish color but in his other appearences it is purple, and in Greetings From Techadon it was more of a violet color.