Back with a Vengeance

Back With a Vengeance is the twenty-sixth episode of Ben 10 and the season two finale.

Plot
A ship flies by and a large block of ice is being taken into the vessel. Inside, aliens speculate the massive ice block and Kevin jumps down and recaps battles he has had. He’s heard of Vilgax, over and over again. He places his Heatblast hand onto the giant ice and melts it to reveal Vilgax’s face. The aliens step back after seeing Vilgax. Kevin says that they were both after for the same thing. Ben, who wields the Omnitrix and has defeated them both in battle.

The Tennysons speculate the amazing sights of the Niagara Falls, hoping they would have a great day. Unfortunately, Gwen finds Ben tweaking around with the Omnitrix. Ben claims that there might be some way to gain better control of it. As he continues to play around with it, the Omnitrix reacts and starts rotating through different alien silhouettes on its own, making Ben think that he must have busted it again, says "maybe, it is some kind of an upgrade", Ben transforms into Upgrade. With amazement, he says other alien names, and he figures out that the Omnitrix also reacts to thoughts. He has unlocked the Omnitrix's Master Control. Wildmutt, looks down into the water, and he looks back at one of the tourists, asking if Max could take a picture of him and his wife. He falls overboard, and Wildmutt changes into Ripjaws to come to the rescue. After picking him up from the water, Ripjaws turns into Stinkfly to fly him back into the ship, safe and sound. Gwen and Max are shocked by Ripjaws turning into Stinkfly.

Back at the ship where Kevin is, he looks at Vilgax, saying that he doesn't look so tough. Vilgax immediately breaks free and punches Kevin away, telling him that he should have never said that. Vilgax throws a pillar straight at Kevin, and pushes him out the window, sending both of them into a Megacruiser battle arena. Kevin says that Vilgax should be grateful for saving his life, but Vilgax gives allegiance to no one. After finding out that Kevin knows a lot about Ben and the Omnitrix, they form a partnership that plans to get the Omnitrix in their hands.

Gwen and Max relax to a snack, Stinkfly is up in the trees, he spits slime into Gwen's pudding, and laughs. Stinkfly is happy that he's able to be an alien for as long as he likes. He throws the profit money he’s gained for giving rides to tourists. Gwen and Max both are very aware of the new feature of what the Omnitrix can do, but they both claim that it might have hidden consequences. Max tells Ben to come to him for a small chat. Stinkfly transforms to XLR8, and instead of listening to what he has to say, XLR8 runs off with his pudding.

Vilgax analyzes Kevin’s DNA, and he explains that his pattern is the same as Ben’s. Kevin’s impatience lets him talk back. They both admit that they lost to Ben, but Vilgax says that with his knowledge, and Kevin’s connection with Ben, will give them victory. Kevin wants to get the situation over with, but they can only do it if the Omnitrix is active. They find the signal immediately.

The Tennysons continue to enjoy their day, and Max decides to take some pictures. Wildvine comes out of nowhere, and decides to dive into the water and bungee himself back up. In a series of photo shoots, Ben continues to play around with the alien forms, and in the lift, he decides to test which alien can hoc the best lugi, Heatblast wins. Vilgax and Kevin arrive, Ben, Gwen, and Max were surprised that Vilgax and Kevin were still alive, especially after the incidents that happened to them. Ben attempts to escape as Grey Matter, but Vilgax was able to grab him. Little did Vilgax know that Ben had unlocked the Master Control, Grey Matter transforms to Diamondhead to escape Vilgax’s hands. Vilgax and Kevin fall down the waterfall while Stinkfly flies Gwen and Max into safety.

Vilgax and Kevin survive the fall, and Vilgax attempts to track Ben’s whereabouts. Cannonbolt falls down on them. At the RV, Max opens up another hidden stash in the RV, and it reveals a Null Void Projector. Max says that it’s the only way to stop Vilgax and Kevin and stop them coming back. Kevin tries his way of luring Cannonbolt, Vilgax insists that they do it his way. He says that they should be able to get Cannonbolt out by using Max and Gwen as bait. Their plan as using them worked, though Max was able to send them to the Null Void. Unfortunately, Diamondhead was dragged in as well, and there find no way out. Vilgax explains that the Null Void is an alternate dimension, where the evil are banished forever.

Outside, Max attempts to enter the Null Void to save Ben, but Gwen insists that he shouldn't. Instead, she decides to herself. After all, Max is the only one who knows how to use the Null Void Projector. Inside the Null Void, Heatblast is being carried by a Null Guardian manipulated by Vilgax. Ben uses strategy to survive the attacks ordered by Vilgax. Gwen enters the Null Void, and encounters danger, but luckily, Gwen has things to prepare herself.

Kevin and Vilgax continue their search for Ben, while Max continues to hold open the portal. He says that Gwen needs to hurry. In an instant, Stinkfly and Gwen find each other, and realize that they need to get out of there. Kevin was able to grab a hold of Gwen before they reached the portal that leads them out of the Null Void, and to make it worse, they were surrounded. Ben had no other choice but to give up and save Gwen by giving up the Omnitrix to Vilgax and Kevin. Ben thinks that it would be a simple trade, but Kevin in an instant threw Gwen away and used a device to painfully tear the Omnitrix of Ben's wrist. The Omnitrix was held in a spherical container, and Kevin takes it for himself, saying that he should be able to use it instead of Vilgax. With a fight amongst themselves in who would get the Omnitrix, Ben and Gwen were able to get out of the Null Void.

Unfortunately, the Omnitrix was seemingly left in the Null Void, and Ben thought he would never get it back. Gwen says that she has a present for Ben. It was the container that held the Omnitrix. Gwen said that Ben may be dumb enough to throw the Omnitrix away, but she's not. In the Null Void, Vilgax and Kevin were going after a decoy, which eventually exploded. Max tells Ben that he owes Gwen a big-time thanks, but Ben had something else in mind, revenges. He transforms into Grey Matter and realizes that he zeroed out the Master Control. Gwen and Grandpa Max laugh about it.

Major Events

 * Ben unlocks the Omnitrix's Master Control, but zeros it out in the end.
 * Vilgax and Kevin are trapped in the Null Void.

Characters

 * Ben Tennyson
 * Gwen Tennyson
 * Max Tennyson

Villains

 * Null Guardians
 * Vilgax
 * Kevin Levin

Aliens Used

 * Upgrade
 * Grey Matter (x8)
 * Diamondhead (x4)
 * XLR8 (x6)
 * Heatblast (x5)
 * Wildvine (x3)
 * Wildmutt (x4)
 * Ripjaws
 * Stinkfly (x6)
 * Four Arms (x3)
 * Cannonbolt (x2)

Trivia

 * Ben figured out the Master Control by mistake.
 * The Null Void's interior is first seen in this episode.
 * There where four deleted scenes in this episode. The first one was right after Ben escaped a Null Guardians mouth. When Ben turned into Cannonbolt he opened up and said "Let's roll out of here!" and Cannonbolt rolled on a circular rock and turned into XLR8. The second one was when Ben kept turning into his aliens while escaping from Vilgax, Kevin, and the Null Guardians. Right after Ben turned into Wildvine he turned into Diamondhead and made his hands sharp and slid down a rock. Then he turned into Heatblast and blasted a few Null Guardians before flying away. The third was when Kevin was removing the Omnitrix. Nothing was really different but it was longer but Ben was knocked out for a couple seconds before waking up and saying he zeroed out the Master Control. The last was when Ben was running away from Kevin. It was also longer where Kevin used Heatblast fireballs, Stinkfly goo, and Diamondhead crystals to try and stop Ben before trying to catch him while flying.