Ken 10

Ken 10 is the forty-sixth episode of Ben 10.

Plot
Ben 10,000 is fighting Vulkanus (as seen in "Perfect Day" and "The Galactic Enforcers") and sends him into the Null-void. He then gets home just in time for Ken's birthday party. The relatives come and gives him gifts; Gwendolyn (Gwen) gives him a rock pet (as seen in "A Change of Face" and "Tough Luck"), Max gives him a hoverboard and he receives an Omnitrix from Ben.

Ben leaves to go fight more crime, Ken turns into XLR8 and races with Ben. While fighting, people and aliens watch the fight (also a kid that looks like Kevin while they were fighting Mot Snikrep).

Ken finds out that Ben put a limiter on the Omnitrix to keep Ken from heroing on his own and is displeased because he won't let him fight. So he becomes friends with Devlin (the kid who looks like Kevin) after playing hoverboard. Gwendolyn talks to Ben about kids and their ways, Ben decides that the next time there's an attack, they'll fight together.

At night, someone tries to attack Ben and Ken. Ben finds the intruder is Kevin. Ben tells Ken to go to his room because he's too strong, unwilling to let him fight despite the promise he made.

The next day, Ken tries to find the Null-Void on his own with Devlin hoping to impress his father by finding out how Kevin escaped the Void, so he turns into Ditto. Ken finds the Null Void chamber and much to his horror discovers that Devlin is the son of Kevin who had attacked the house last night in search of the chamber using Kevin's original mutant form. Devlin releases his father just in time for Ben to arrive. Kevin reveals that being imprisoned in the void was the best thing that ever happened to him as he's absorbed that powers of 11 000 aliens and transforms into a even more monstrous form than before. Kevin mercilessly attacks Ben, Ken and even his own son Devlin. While Ben takes the fight outside Ken has a idea to defeat Kevin.

Ben still fights Kevin, but as before weakens Ben, so he reverts to human form. Ken comes in (surprisingly he is Grey Matter) and later switches in to Spitter, then Buzzshock. Ken reveals he used Grey Matter's brain to remove the Omnitrix's limiter so he can switch forms at will. Kevin grabs Ken and is about to throw him, but Devlin comes in to defend him. Devlin explains why he freed Kevin, he wished his father would've cared about seeing his son again but instead doesn't care at all as he is only willing to kill the Tennysons. Devlin cries upon the realization but then resumes fighting against his father. Ken turns into XLR8. Devlin and XLR8 are thrown away and XLR8 reverts back into Ken who passes out.

Ben is scold and sees what happened then turns into Way Big to mercilessly crush Kevin, Kevin reverts back into human form, but is still strong. Kevin is about to kill Ben and Ken, but Devlin imprisons Kevin in a Null Void Grenade (small grenade-like device capable of sucking aliens inside of it). Max states that he has a special place reserved for Kevin so he can't absorb anymore Alien DNA. Ken asks Ben if he can use all ten thousand of his heroes, but Ben says don't push your luck.

Devlin was about to leave until Max grabbed Devlin. Ken says he should stay with him, so Devlin becomes part of the Tennyson family. Later, Ken's rock pet regenerates and is alive again making him happy.

Major Events

 * Ben's son, Kenny celebrates his 10th birthday.
 * Kenny obtains his own Omnitrix.
 * Kenny meets Devlin.
 * Kevin escapes from the Null Void, but gets defeated by Ben as Way Big.
 * Devlin moves in with the Tennysons.

Debuts

 * Kenny Tennyson
 * Devlin Levin
 * Kevin 11,000

Characters

 * Ben 10,000 (main character of this episode)
 * Kenny Tennyson
 * Devlin Levin
 * Gwen Tennyson
 * Grandpa Max
 * Ken's friends (Billy Alien, another unnamed alien kid and a girl Gwen)

Villains

 * Kevin Levin (main and true villain of this episode)
 * Devlin Levin (Temporarily)
 * Vulkanus
 * Mot Snikrep

Aliens Used By Ben 10,000

 * Fourarms (x4)
 * XLR8 (x4)
 * Cannonbolt (x2)
 * Heatblast
 * Diamondhead (x2)
 * Spitter
 * Articguana
 * Benmummyl
 * Way Big

Aliens Used By Ken

 * XLR8 (x2)
 * Buzzshock (x2)
 * Wildvine
 * Grey Matter (x2)
 * Ditto
 * Spitter

Errors

 * Though the party is for Kenny's 10th birthday, his cake is erroneously depicted with 11 candles.
 * When Kenny was fighting Kevin, the Omnitrix timed out even though he had unlocked the master control.

Trivia

 * At the birthday party for Kenny, one of his alien friends looks like the character of 'Billy' from The Grim Adventures of Billy and Mandy. To drive the point home, he has the same voice actor as Billy.
 * Because of Paradox's explanation in the episode Ben 10,000 Returns, Ken 10 is now a canon episode.
 * At the end of the episode, Ben asks Devlin if he wants to move in with him, much like he did with his father Kevin in Kevin 11. Unlike his father, Devlin accepts.
 * This is the only episode of the original Ben 10 series that doesn't feature young Ben and Gwen.
 * The girl at Kenny's birthday might be his sister, Gwen.
 * This episode marks the first instance of the Omnitrix being used as a communicator. This feature isn't seen again until the sequel series.