Back in Action: Alien Universe (or simply Back in Action) is the sequel series to Ben 10: Alien Universe announced on August 19, 2012 that premiered on August 29, 2012.

The series experienced a five-year hiatus but returned on October 4, 2019.

Accolades and Fans


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Accolade Date
Featured Series February 2012
Featured Episode: The Alternative June 2018
Featured Episode: Ten Plus Twenty November 2018
Featured Character: Sii February 2019


Main article: List of Back in Action: Alien Universe episodes

3 seasons were planned, arriving at 24, 15, and 8 episodes (for a total of 47 episodes), respectively. 5 completed Shorts are also available.

Seasons Episodes
1 24
2 15
3 8
Shorts 6+

Potential Spoilers Ahead!

Season 1

17 year old Ben unravels the plot of the Thep Khufan Armada, and together with many of his closest friends and newest allies, he must thwart its shifty Commander or sacrifice the Earth and universe to him.

Season 2

In the aftermath of a great loss, Ben is faced with troubles at home as a being armed with their own Omnitrix runs amok in Bellwood. Meanwhile, two infamous prisoners of Incarcecon in the Null Void are plotting their escape - Vilgax and Malevolence.

Season 3

Ben hides from the most dangerous villain between all timelines - his own future - on a mysterious prison planet. While there, he is forced to team up with his worst enemies for their survival, as well as alternate timeline Omnitrix wielders, Bens, and the lost love of his life.


Potential Spoilers Ahead!



Ben's Aliens

Through the Assault Omnitrix, Ben has access to over 50 alien transformations, and Future Ben countless more. Bold aliens have been reunlocked since Recalibration with the new Assault Omnitrix.

Unique Season 1 Aliens

Season 2 Aliens

Unique Ultimate Aliens

Classic Aliens

  • Heatblast
  • Diamondhead
  • XLR8
  • Four Arms
  • Ghostfreak
  • Stinkfly
  • Grey Matter
  • Upgrade
  • Cannonbolt
  • Wildvine
  • Way Big
  • Articguana
  • Benmummy
  • Benwolf
  • Buzzshock
  • Eye Guy
  • Ditto
  • Benvicktor
  • Swampfire
  • Echo Echo
  • Humongousaur
  • Jetray
  • Big Chill
  • Chromastone
  • Brainstorm
  • Spidermonkey
  • Goop
  • Alien X (disabled in Season 2)
  • Rath
  • Lodestar
  • Fasttrack
  • Nanomech
  • Astrodactyl
  • Water Hazard
  • Terraspin
  • NRG
  • Forge (Armodrillo)
  • AmpFibian

Classic Ultimate Aliens

  • Ultimate Big Chill
  • Ultimate Wildmutt
  • Ultimate Cannonbolt
  • Ultimate Swampfire
  • Ultimate Echo Echo
  • Ultimate Humungousaur
  • Ultimate Way Big
  • Ultimate Spidermonkey

Future Aliens

Mentioned-Only Aliens

Major Spells Used


Differences from canon

  • Ben received the Assault Omnitrix instead of the final Omnitrix.
  • Ben named his Talpaedan transformation Forge instead of Armodrillo.
  • The Plumbers' origin on Earth happened differently, as explained in Foreverlasting.
  • Carl Nesmith's Captain Nemesis was only a TV hero in this timeline, akin to Kangaroo Kommando.
    • He did still become a very high-profile arms manufacturer and later super villain.
  • Much of Omniverse did not transpire. Specific distinctions are mentioned throughout the series.
  • Where Omniverse erroneously continued with Ben still 16, in spite of too much time passing during Ultimate Alien, Back in Action proceeds with Ben instantly turning 17.
  • Some of Ben's transformations have different appearances. Gwen's Anodite form also reprises its Alien Force/Ultimate Alien appearance.
    • Grey Matter appears with his Omnitrix on his chest, as it would have had he appeared in Ultimate Alien. As of Hit and Miss, he has donned his Omniverse attire.
    • Articguana, Buzzshock, and Stinkfly have their original series appearances.
  • While Primus and the Codon Stream act as backups, the Hidden Universe acts as a local hub for transformations, housing all available transformations. In this timeline, the Hidden Universe was available in the original Omnitrix and Assault Omnitrix but not the Ultimatrix.
  • All canon "mutant" characters are alien hybrids.
  • Gwen's school is instead called Dwayne University, in honor of Dwayne McDuffie.
    • Hex is not a Professor at Gwen's school.

Second Run retcons

  • Originally in Ten Plus Twenty, it was suggested a presidential election was forthcoming (lining up with the real world upcoming 2012 election). To align with some upcoming content in Season 2, it was changed to reference the incumbent president and a forthcoming midterm election.
  • Originally, Malevolence's patterns were green. To distinguish from Julie/Ken and Upgrade, this was changed to purple befitting his former royalty.
  • Originally in Revelation, Malevolence specified his successor was a Mechamorph. The line was changed to be a more generic "insurgents," to make way for the Chimera Sui Generis successor Vil, who Malevolence kills in Never Set in Stone.


  • On YouTube, the show was referred to as Ben 10: Alien Universe Re-Animated.
  • The logo was originally created by NickFusi0n.
  • Every third episode is four parts. The premiere episode Infernosphere was first, followed by No Strings Attached. Plight of Pinocchio is next in line for this treatment.
  • The series was going to be 3 seasons.
  • Many of the second run's new concepts are borrowed from the scrapped reboot of canon These Befallen.
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