The two-disc set starts off with a crossover episode where The Secret Saturdays are invited to Bellwood by Grandpa Max since the current threat facing the Earth appears to include a race of cryptids called Chupacabras. The Saturdays are particularly skilled with unusual Earth creatures and, while they might appear to be alien to Ben, this new threat needs the Saturdays' particular expertise. As with any great crossover though, it turns out the real threat is that one of Ben's enemies has joined forces with one of the Saturdays'. Dr. Animo has revived V.V. Argost (a megalomaniac yeti) and the combination of cryptid and alien technologies is going to make both team of superheroes work extra hard to stop their plans.
Another non-Incursean-centric episodes include one where Ben, Driba and Blukic head out on a personal mystery as they track down an unusual Mr. Smoothy store that seems to constantly disappear and reappear. When they find it, they learn that it is managed by Holkestar who hopes to open a multidimensional store that exists in all universes at the same time. Of course, something goes wrong and Ben, the Galvans and Holkestar all end up stuck in a parallel universe where Ben is a well-known hero, but without Grandpa Max's guidance. The result is that while "Ben 23" is still a good fighter trying to stop aliens, he has an odd view of his responsibilities.
Before jumping into the Incursean Empire episodes, there is one other episode that is worth mentioning, "Ben Again." In this episode, Eon attacks both the young Ben and the older Ben in such a way to cause their minds to switch. The younger Ben finds himself in the older one's body with the older one's abilities and, thankfully, with Gwen and Max's guidance to help figure out how to solve the problem at hand. Meanwhile, the older Ben in the younger's body works with the younger Gwen and Max team as Professor Paradox shows up and explains that a Time War has broken out and Eon is trying to take control of all timelines. The only way to keep the enemy from winning is to use a device that Paradox has and must be kept away from Eon at all costs. In general, this is an amusing episode that shows how much Ben has grown up since the series' first episodes.
Ben 10: Omniverse: Aliens at War contains five episodes that have to deal with the frog forces, led by Emperor Milleous and his daughter Attea. The earlier two, "Tummy Trouble" and "Vilgax Must Croak" show that the empire is growing and taking over more planets. In "Tummy Trouble," Ben's Upchuck alien isn't feeling very well and he and Rook decide to go to the Gourmand homeworld of Peptos XI. There they learn that civil war has broken out over trying to decide how best to handle an impending invasion by the Incurseans. It seems that they have abducted their queen and the two Gourmand races disagree about how to resolve the impending conflict.
In "Vilgax Must Croak," Ben and his team are escorting the captured Vilgax to a maximum security prison. The prison itself is being evacuated and Vilgax will be the only inmate. Everything will be automated and no one will even be allowed in the solar system. Unfortunately, it seems the Incurseans are planning on taking out Vilgax in a plot to lower the morale of Vilgax's homeworld, the next stop on the Incursean border expansion. In an ironic twist, this means that Ben must actually protect his oldest enemy.
The volume wraps up with the Incurseans invading Rook's homeworld, and when that is halted, the Incurseans decide to focus on Earth. In an unexpected twist, the Incurseans succeed in taking over the human homeworld. This is primarily due to the Empire's alliance with Dr. Psychobos who controls mutated Way Bigs, dubbed Way Bads, that act as a constant threat against rebellion. Ben is forced into exile and is told never to return. In the second episode in this two-parter, "The Frogs of War," a resistance is established. Heading up the effort is Gwen, Kevin, Rook, Blukic and Argit, but they are in dire need of a decisive victory. When the team finds themselves double-crossed, they are also freed by an unlikely ally. A muscular Incursean named Bullfrag helps them escape, but the resistance fighters aren't sure at first if they can trust this new ally.
As for special features, like past Omniverse volumes, this release only comes with descriptions of some of Ben's aliens. In this case, the DVD focuses on Ampfibian, Cannonbolt and Terraspin. That being said, I found this particular volume a bit more enjoyable than the past two. While there was a common thread tying most of the episodes in those volumes together, for some reason, I found the Incursean Empire story arc a bit more enjoyable than the Malware one seen before. Even if you've only been casually following the Omniverse series so far, Aliens at War is a good collection to watch.