A showdown between Vilgax and two of his greatest enemies.
Vilgax travels to Ghostfreak's prison to free him and learn the Omnitrix's secrets. When he gets betrayed and his planet gets conquered by the ghost alien, he's forced to team up with Ben, Gwen and Kevin to save his planet.- Acid Attack: The Monster of the Week at the beginning of the episode spat acid on Kevin's foot and Humungousaur's tail
- Cobweb Jungle: Vilgaxia is overrun with cobwebs after Ghostfreak takes over. It is unknown whether this is because all of the citizens were possessed and busy, or whether they put it there as if it was there hive. We later see that the Anur System has similar cobwebs linking all of its planets in Ben 10: Omniverse, so there may be a connection.
- Didn't Think This Through: Ben comes up with a plan to defeat Ghostfreak by letting him possess him and trapping him in the Omnitrix when he transforms into him. All this accomplishes is allowing Ghostfreak to control his body, nearly getting Gwen and Kevin killed, and almost guaranteeing Ghostfreak's victory when he attempts to possess Vilgax. It's only because Vilgax weakened Ghostfreak with bright light that Ben is able to take back control long enough to change back. Gwen and Kevin both call him out on how it was a really shitty idea.
- Egopolis: The name of Vilgax's planet? Vilgaxia. For bonus points, supplementary materials indicate that the planet originally had a different name but was renamed Vilgaxia after Vilgax took control of it by force in his backstory.
- Enemy Mine: Vilgax is forced to team up with Ben and his team after Ghostfreak takes over his planet.
- Evil vs. Evil: Vilgax calls upon Ben's team to fight against Ghostfreak. Later, when Ben gets absorbed by the ghost alien and Gwen and Kevin are defeated, Vilgax and Ghostfreak go at each other one-on-one.
- Forced Transformation: After taking over the planet, Ghostfreak has transformed its inhabitants into Ectonurite extensions of his hive mind. When he's dealt with, they apparently all go back to normal.
- Fusion Dance: Ghostfreak intends to take over both Ben and Vilgax to make himself unstoppable.
- "I Know You Are in There Somewhere" Fight: Gwen does this to Ben after he transforms into Ghostfreak and gets taken over by him. It doesn't work.
- Leaning on the Fourth Wall: Ben spends much of the episode mocking Vilgax’s Villain Decay.
- Stealing the Credit: Vilgax receives the praise for saving his planet from the citizens, and Ben agrees not to share the truth.
- Tailor-Made Prison: Ghostfreak is shown at the beginning of the episode to be trapped in a space station that keeps him incarcerated in a beam of concentrated sunlight.
- Tempting Fate: When Ben turns into Ghostfreak, Gwen is not impressed by the realization this was his plan. Ben reassures her he can control him, but is instantly proven wrong when Ghostfreak takes control, as symbolized by the Omnitrix symbol disappearing into his body and his green eye turning into Ghostfreak's natural eye color.
- Transformation of the Possessed: Everyone that Ghostfreak possesses gets linked into his Hive Mind, and takes on the appearance of his original Omnitrix transformation. Luckily, Kevin's mutated form is immune.
- Villain with Good Publicity: Vilgax, at least on his planet. When they are freed from Ghostfreak's grasp, the people cheer for Vilgax.
- Whack-a-Monster: Ben and his team do this when fighting the alien in the mini golf course at the beginning of the episode.
- What the Hell, Hero?: After Ben is able to regain control of his body and change back, Gwen and Kevin call him out on his foolish plan and almost getting them killed. Ben does himself no favors by acting so casual about the whole thing.Ben: Aww, you guys missed the whole thing!
Kevin: We saw enough.
Gwen: Ben, that was really, really stupid!
Ben: Except for the part where it worked!
Kevin: And we almost got creamed in the process! You're not in this alone, or did you forget?
Ben: So, no victory parade?
