Vulkanus first appears using Argit to help kidnap Kevin, in order to get the money he's owed. He forces Kevin to absorb taydenite to create an endless amount. He is defeated when John and Gwen arrive.
He next appears when Gwen creates an alternate future, ruling it with P'andor. The Earth is covered in lava, similar to his home planet. He returns in the regular timeline as a part of the Negative 10, hired by Albedo. Once they are defeated, Vulkanus is arrested.
Vulkanus comes back after buying the Earth, now having loads of money. He tries to change the surface of the Earth into lava, similar to the alternate future he appeared in. His plans are stopped, and he escapes. Sometime after this, Aggregor steals $10 million worth of taydenite from him to pay Argit, who double crosses him. Argit plans to sell the list that Aggregor wanted on the black market, and John and the others go after Vulkanus, being one rich enough to buy it. He admits that he had been robbed, and can't afford it.
Sometime after this, Vulkanus tracks his taydenite to Argit, and chases him down, stranding him on an island in the ocean.
During the Clone Wars, Vulkanus and several other bounty hunters go after Kevin, a bounty placed on his head. Kevin and Eddy defeat them, and hold them captive. Kevin later tortures Vulkanus to reveal who hired him, Vulkanus revealing it to be Ragnarok. Kevin sends back to jail with fresh wounds.
Vulkanus briefly appears in an alternate dimension prison.
Vulkanus appears as owner of the Mythril Mines, with Charmcaster's Stone Creatures as his workers. He's an ex-boyfriend of Sakura, who dumped him and took all his money. Upon Sakura's return, Vulkanus attacked her and her group. When Ghostfreak leads an army of goblins to attack the mines, Vulkanus is forced to team up with Sakura, and they defend the mountain. Once the battle was over, Vulkanus said that "they were even."
Vulkanus appears along with bounty hunters to hunt Ryder. He buys a pet Crabdozer from Khyber. He later teams up with Seebik, the two sharing the idea of a heated Earth.
