The Best Episodes of Ben 10: Ultimate Alien

As the team makes its final attempt to stop Aggregor, they find an unexpected ally, and one person will make a fateful decision with lasting repercussions.

Director: Dan Riba

Writer: Joe Casey, Joe Kelly

Then team encounters another of Aggregor's escaped prisoners, Andreas, whom Argit is using as part of a scheme against the Forever Knights.

Director: Dan Riba

Writer: Ernie Altbacker, Joe Casey, Joe Kelly

Aggregor has absorbed all the powers of his captured aliens. Now he's after the Map of Infinity.

Director: Matt Youngberg

Writer: Joe Casey, Joe Kelly

Azmuth reveals the origin of the sword and how he first encountered Old George. Ben comes to a decision on how to handle the Daigon.

Director: Matt Youngberg

Writer: Peter David

Gwen and co revisit Legerdomain in hopes of rescuing Charmcaster.

Director: Matt Youngberg

Writer: David McDermott, Brian Swenlin

After Darkstar opens the Door to Anywhere, Charmcaster comes through, and the two team up to give Ben, Gwen, and Kevin the fight of a lifetime.

Director: Dan Riba

Writer: Geoffrey Thorne

Ben gets an offer to star in his own video game, but the designer's real motives are part of a plan to destroy Ben.

Director: Dan Riba

Writer: Joe Casey, Joe Kelly

The team encounters another alien who escaped from Aggregor and, through him, learns more about Aggregor's goals.

Director: Butch Lukic

Writer: Charlotte Fullerton, Joe Casey, Joe Kelly

Ra'ad, the last of Aggregor's escaped prisoners, attacks Ben and informs the team of the true fate of his comrades. He finds a safe hiding place but one that endangers Ben in the process.

Director: Dan Riba

Writer: Len Uhley, Joe Casey, Duncan Rouleau

Ben meets his hero, Captain Nemesis, who's become jealous of all the attention Ben attracts.

Director: Matt Youngberg

Writer: Steven Barnes, Joe Casey, Joe Kelly

With the fourth piece of the Map of Infinity almost in Aggregor's clutches, the gang chase him through the artificial planetoid known as Perplexahedron.

Director: Matt Youngberg

Writer: Joe Casey, Joe Kelly

Kevin's out for payback on anyone who has ever crossed him. His next stop is a prison in the Null Void. Ben and Gwen try to stop him, where Ben comes to a grim decision.

Director: Butch Lukic

Writer: Joe Casey, Joe Kelly

Argit asks Ben and Gwen for protection from Kevin, so they take him to the nearest Plumbers Academy, but that won't stop Kevin.

Director: Matt Youngberg

Writer: Len Uhley, Joe Casey, Duncan Rouleau

Kevin starts going after Plumbers kids to gain more power. Ben and Gwen continue to argue about how to handle the situation. Gwen tries to find someone who will help her cure Kevin.

Director: Dan Riba

Writer: Charlotte Fullerton, Joe Casey, Joe Kelly

Final confrontation with Kevin. While Gwen makes a last ditch effort to save Kevin, Ben fights an all out battle with Kevin.

Director: Dan Riba

Writer: Joe Casey, Joe Kelly

A mysterious alien girl named Eunice has no memory and is being hunted by Sunder. While evading Sunder, Ben soon discovers that Eunice has nature-based abilities.

Director: Matt Youngberg

Writer: Joe Casey, Joe Kelly

Following a visit from Paradox after a fight with Eon, Ben 10,000 arrives 20 years from the future to seek the aid of his past counterpart in tracking down Eon.

Director: Matt Youngberg

Writer: Joe Casey, Joe Kelly

Movie starlet Jennifer Nocturne is recaptured by the evil Captain Nemesis!

Director: Butch Lukic

Writer: Len Uhley

Ben is supposed to attend a tournament to support his girlfriend, but the Forever Knights are trying to break into a museum. Ben tries to use the Ultimatrix to handle all his obligations.

Director: Butch Lukic

Writer: Len Uhley

P'Andor, escaped from Aggregor, now wants help to escape his encapsulating suit, but Kevin's the first to perceive that that's a fatally bad idea.

Director: Matt Youngberg

Writer: Marty Isenberg, Joe Casey, Joe Kelly

Aggregor has all five aliens. The Plumbers manage to disable Aggregor's ship, forcing Aggregor to find a new way to absorb their powers. The team makes a last ditch effort to save the alien prisoners.

Director: Matt Youngberg

Writer: Joe Casey, Joe Kelly, Matt Youngberg

Aggregor escapes to a magical dimension. Gwen asks for Charmcaster's help to pursue him. The team learns about Charmcaster's past and why she's willing to help them now.

Director: Butch Lukic

Writer: Joe Casey, Joe Kelly

Victor Validus resurfaces and attacks Ben at night. Elena Validus and the nanochips return.

Director: Butch Lukic

Writer: Joe Casey, Joe Kelly, Stan Berkowitz

The Forever Knights unleash an evil force mistaken for an ancient weapon.

Director: Dan Riba

Writer: Len Uhley, Joe Casey, Duncan Rouleau

Gwen has always been a multi-tasker, trying to juggle school, hobbies, friends and her work as a hero, waking up early and going to sleep late. But Gwen's already packed day is about to get worse when Dr. Animo attacks with an army of giant frogs and Gwen is forced to make a hard choice.

Director: Matt Youngberg

Writer: Joe Casey, Joe Kelly