Kevin Levin (Classic)/OV flashbacks

Kevin is found by the Rooters, who did experiments with his Osmosian powers on Alan Albright, Helen Wheels, Manny Armstrong and Pierce Wheels, transforming them into the Amalgam Kids, making them do nasty things. After that, Kevin fled, only with Servantis controlling his memories, convincing him that he had "alien blood".

During the time that he was associated with the Rooters, Kevin first met Argit when he gave a caged Argit a leaf to eat. Kevin then says that he is going back to Earth and save it and intends to take down Ben.

Eventually on Earth, Kevin discovers Argit and threatens him to start running and he and the Amalgam Kids confronted Ben, Gwen, and Max and Kevin fired a blast at Ben. Ben manages to avoid the shot and transforms into Eye Guy. Eye Guy pins Kevin down, However, Kevin did this to get Ben to come closer and touches the Omnitrix causing Kevin to mutate again. Kevin, like Ben stated, starts to go insane again and even attacks his allies the Amalgam Kids. Kevin was eventually stopped by Argit who used his quills. Kevin and the Amalgam Kids were sent back to the Null Void but an enraged Servantis wiped out their memories and sent them away. Servantis then abandoned the plan to destroy Ben after Ben stopped wearing the Omnitrix.

In the Null Void, Kevin and Argit are moving some objects around and they both talk about how difficult it is to bring the objects together. Suddenly, a robot named Otto arrives and says that he is going to use the objects to help them get out of the Null Void. Otto tricks Kevin and Argit into turning on the device and escapes without them, leaving now-dismayed Kevin and Argit trapped in the Null Void.

At some point later, Kevin was brought out of the Null Void by Thaddeus J. Collins, who was being possessed by Zs'Skayr, and tied to the Null Void portal using Plumber technology. Collins asked Kevin to use his absorbing powers to mine Hedorium underground. Kevin was mining for Hedorium in a dark cave when he encounters Ben (who was accompanied by his cousins Gwen and Lucy and his friends Cooper and Jonesy). After Cooper examines the technology as Kevin asks him to disconnect him from the portal, Ben disagrees with Kevin's request as he has done a lot of bad deeds to him. Kevin then tells Ben that the Earth would be in danger, Ben takes Lucy and Jonesy to find out about the problem as Gwen and Cooper deal with Kevin. While Ben as Eye Guy, Lucy and Jonesy fight Grandpa Max holding a weapon, Kevin teases Cooper about being Gwen's boyfriend but both of them stated they were just friends. Kevin teases and thinks he is a better guy, leaving Gwen raged and walks away. As Eye Guy, Lucy, and Jonesy defeat Max, Cooper tried to pull the connection but failed. He then re-programmed Kevin's connection to let him pull the portal like a kite. Gwen blasts at the portal to separate the ionic bonds as they headed to join Ben, Lucy and Jonesy. Ben laughs at Kevin because he is still connected to the portal, Kevin says it is better than being stuck to one spot. As the group walked further into the caves, they see a portal which things come out off. They head up only to see Thaddeus J.Collins, who is revealed to the children to be Zs'Skayr in disguise, and that the portal is for the Ectonurites to come in from their homeworld. Gwen is surprised that Kevin has been helping Zs'Skayr. The other Ectonurites are inside the bodies and controlling the grown ups. Due to the collective efforts of all the kids, everyone was saved when suddenly the Null Void portal starts to pull Kevin. Ben, Gwen, Lucy, Jonesy and Cooper help to pull Kevin in order to prevent him from being pulled into the Null Void portal, but they fail to do so when Ben loses his grip on Kevin's hand, leaving Kevin getting pulled back into the Null Void.

At some point later, Kevin and Argit managed to escape from the Null Void at the same time and two years after breaking away from Servantis, Kevin began work on his car, not satisfied with a simple standard model he began outfitting it with Alien Tech, and to this end traveled to Khoros to acquire a Tetramand engine block for it. Since the tech couldn't be given to an outsider, he wooed the then teenage Princess Looma Red Wind and successfully defeated her combat earning the right to marry her in three years thereby making him a part of the family and was given the engine as a gift.