Rules of Engagement

Rules Of Engagement is the twenty-eighth episode of Ben 10: Omniverse.

Plot
At a jewelry store, Fistina is seen breaking out through the front door with some stolen jewelry. Ben, as XLR8, quickly takes the jewellery and runs off. Fistina fires her hand at Ben and attempts to grab him but Ben speeds up avoiding it. Fistina attempts to crush Ben but he dodges out of the way. Ben taunts Fistina while she attempts to hit him with her fist rocket again. Ben then starts to run circles around Fistina and she eventually gets spun around and her head flies off onto a wall. Rook arrives at the scene on his Proto-TRUK and pulls Fistina's head off the wall. Rook warns Ben on Fistina's body attempting to attack Ben but Rook traps the body in a net using his Proto-Tool. Fistina's body falls on Ben and Fistina is impressed with Rook's tactics. Ben turns back to normal and he asks Fistina why she attacked the jewelry store. Fistina says she likes pretty things and starts to flirt with Rook. Ben and Rook stare on confusingly and Ben walks over to some televisions noticing Julie is back in town. Ben then decides to see her before turning in Fistina and Fistina continues to flirt with Rook. Over at a tennis court, Julie is practising tennis while a gentleman is taking photos of her impressed with her skills. Ben arrives and jumps from the Proto-TRUK and asks Julie why she hasn't tell him that she was back home. Julie says she has been busy and the gentleman walks over with Ben wanting to know what his name is. Julie introduces him to Hervé, her new boyfriend. Ben looks on shocked and confused.

Ben wants to know why Julie found a new boyfriend and Julie says that Ben had broken it off. Ben is confused but Julie tells him to remember the last time they spoke together. A flashback goes to 16 year old Ben in his room playing Sumo Slammers. He starts talking to Julie but he also starts yelling out to the game at the same time. Julie, believing Ben has broke it off, turns off her phone and the flashback ends. Ben then says the he might have broke up with Julie and she says that she now has someone that puts her first and she and Hervé start to walk off. Ben stops the two but Hervé says that everything has been said and he and Julie attempt to walk off again. Ben transforms into Bloxx and builds up a wall stopping the two once again. Julie gives Ben a chance to talk and Ben says that he will start to put her first unless the world needs saving. Suddenly, Ester appears saying the Kraaho need his help from an attacker. Ben decides to go but Ester, thinking Julie and Hervé are Gwen and Kevin, grabs them and takes them aboard the Proto-TRUK. Inside, Ben introduces Julie to Ester saying she and the rest of her people have been living in Undertown. Ben then says that things are complicated with Julie and Hervé attempts to say something but Fistina threatens him if he blocks her view of Rook. Rook says that she is a thief and his unwanted but Fistina just flirts with him more. At Undertown, Ben's group arrive at the Kraaho side where the Kraaho are seen being attacked by Looma Red Wind. Ben is shocked to see her while she is happy to see her "husband."

Princess Looma starts hugging Ben while Rook explains to Julie that his fur makes him too warm in the Kraaho heat. Ester attempts to attack Looma but Looma easily throws her off. Looma then continues to attack the Kraaho but Ben transforms into Armodrillo and starts shaking the ground at her. Looma strikes the ground with her fist sending a wave of rubble at Ben. Ben asks her to stop attacking everything but Looma says she needs a good one. Ester then tells Looma that she will stop her and Looma is excited about fighting the leader. However, Rook starts shooting at Looma while Ben attempts to charge her. Looma punches Ben into Rook while Ester grabs onto Looma. Looma grabs Ester's arms and starts tying her up and throws her into Julie. Ben turns back to normal and yells at Looma wanting to know what she is doing. Looma then says that she needs to collect four items for the wedding: something conquered, something bruised, something severed, and something blue. Ben tells her that she is hurting people but Looma says that the Kraaho could be easily conquered due to them being defeated by Ben already. Ester yells at Looma and Looma looks at Rook noticing him being something blue. Rook is sweating frequently telling Looma that he is a Plumber, not a wedding favor.

Looma attempts to grab at Rook but Fistina bursts from the Proto-TRUK and fires her fist rocket at Looma attacking her. Fistina fires another fist rocket at Looma and damages her once more. Fistina charges at Looma while Julie wants to know how many girls Ben is involved with. Ben doesn't know himself while Fistina and Looma are fighting and arguing back and forth. Looma attacks Fistina and knocks off her fist now noticing something severed. Ben yells at Looma and he then transforms into Humungousaur and he charges at Looma. Looma easily tosses Ben away and she puts Fistina's arm, Rook, Julie, Ester, and Hervé all in a brown bag and flies off on her space ship. Ben transforms back to normal and Fistina worries for Rook. Ben yells at Fistina saying they could catch up if she hasn't destroyed the Proto-TRUK but she just says she did it out of love. Ben, annoyed, transforms into Jury Rigg and uses parts of the Proto-TRUK and creates his newest ride: the Tenn-Speed. Ben gets on his new cycle and Fistina joins him saying she could track her severed first. Ben then drives off out into the city. Inside Looma's bag, Julie says she gets the feeling of how Santa's toys feel. Rook says he is still recooperating. Ester untangles hers arms. Hervé complains about Ben, but Julie tells him about the good Ben does and advises him to give Ben a break. Ester questions Julie whether is she completely broken up with Ben.

At Ben's house, Sandra answers the door noticing Princess Looma and confirms to her that Ben is her son. Looma is excited to see her "mother" and introduces herself to Sandra. Sandra is confused calling for Carl. Sandra then says to Looma that Ben has never mentioned her but Rook uses the Proto-Tool to free himself, Ester, Julie, and Hervé from the bag and they start to run off. Looma uses her hammer to stop them and Ester grabs onto Looma from behind. Looma tosses her off and grabs onto Rook who as attempting to kick her. Looma also grabs onto Ester's fist but overhears Sandra saying Julie was Ben's girlfriend and drops them with Looma saying she has a "rival." Ben and Fistina arrive but Looma quickly tosses Hervé into Ben knocking him down. Ben gets back up and transforms into Ball Weevil and wraps up Fistina in plasma goo. Ben tells his mom to head inside and yells at Looma saying the ritual over. Looma breaks out of the plasma goo and traps Ben in it and tosses him onto a wall. Fistina attempts to attack Looma but Looma knocks Fistina into Rook and Ester. Looma then challenges Julie to a battle threatening to destroy the Earth if anyone interferes in the fight. Julie agrees and whistles and Ship suddenly arrives from her tennis bag. Ship then merges onto Julie forming the battle suit and Looma begins to attack Julie with an energy blast from her hammer. Julie fires back with an energy blast of her own blocking the attack. Ben tells Julie to be careful as Julie and Looma continue their fight. Looma knocks away Julie and an attacking Fistina but Julie manages to fight back. Ester and Rook attempt to pull Ben off the goo but Ben says that he can't turn back to normal. Rook then uses his Proto-Tool to start cutting away at the goo while Looma and Julie continue to fight. Hervé is seen taking photographs of the fight while Looma knocks Julie back closer to Ben's house. Ship de-merges from Julie and Looma attempts to finish off Julie. However, Ben is freed and Rook tosses Ben near Julie who uses her tennis racket to send Ben crashing into Looma. Looma is knocked backwards while Ben lands on a nearby car and turns back to normal and then passes out.

Looma says the she is no longer worth of Ben and says that Julie is now "betrothed" to him. Looma hugs Ben one last time while Rook is surprised that she is taking defeat well. Looma then threatens Julie once more and leaves on her ship. Ben pets Ship happy to see him and Ben asks Julie that she wants to go to Mr. Smoothy. Julie then says that just because she saved him doesn't mean that they are soulmates. Ben understands and asks if they could still be friends. Julie says that they will always be friends and she walks off with Hervé with both of them agreeing not liking Mr. Smoothy. Ben is surprised by this and Ester decides to go back home to help clean up. Ben agrees to help her out and they both walk off with Ester saying she likes Mr. Smoothy. Fistina continues to flirt with Rook but Rook arrests her and takes her away.

Major Events

 * Julie Yamamoto (both flashback and present), Ship, and Sandra Tennyson make their Omniverse debuts.
 * Hervé makes his debut.
 * Ben and Julie are now officially broken up, but they are still friends.
 * Princess Looma returns and is no longer Ben's fiancée.
 * Ben builds the Tenn-Speed cycle from Rook's Proto-TRUK using Jury Rigg.

Debuts

 * Hervé (first-appearance)

Omniverse Debuts

 * Julie Yamamoto (both flashback and present)
 * Ship
 * Sandra Tennyson

Characters

 * Ben Tennyson (flashback 16 year old and present 16 year old)
 * Rook Blonko
 * Julie Yamamoto (first re-appearance)
 * Ship (first re-appearance)
 * Ester
 * Kraaho
 * Sandra Tennyson (first re-appearance)
 * Hervé (debut)
 * Pakmar (cameo)

Villains

 * Princess Looma

Neutral

 * Fistina

Aliens Used

 * XLR8 (off screen transformation)
 * Bloxx
 * Armodrillo
 * Humungousaur
 * Jury Rigg
 * Ball Weevil

Errors

 * During the second fight scene with Looma Red Wind, Rook didn't have his Proto-Tool with him. Right as Ben and Fistina pulled up to his house on the Tenn-Speed, Rook had the Proto-Tool with him.
 * When Armodrillo was tickling Looma with his drill, the grey on his head was yellow.
 * In one scene, the green ten on the Tenn-Speed Cycle was black.
 * In one scene, Rook's Plumber Badge was all black.
 * When XLR8 was running, his Omnitrix symbol is missing.
 * The Looma's ship, ben's tenn speed cycle, and car are in different position

Allusions

 * When Ben finished making Tenn-Speed and is ready to leave, he says "Here comes the groom." This statement is a parody off of the phrase "here comes the bride."

Trivia

 * It is revealed in this episode that Fistina has a crush on Rook.
 * When Ben is flashing back to his unintentional break-up with Julie, he can be seen battling against a Sumo Slammers player with the screen-name of "Derrick W."
 * The game seemed to be based on Street Fighter.
 * Ester mistook Julie and Hervé for Gwen and Kevin, whom she has not met yet.
 * The flashback in the episode takes place after The Ultimate Enemy: Part 2, due to Julie still being with Ben at the end of the episode.