Manny Armstrong

Manny Armstrong is a Plumber's kid introduced in Ben 10: Alien Force. A teenage Tetramand, as well as Helen Wheel's partner, he possesses the same appearance and powers similar to Ben's alien Fourarms, though he's a lot smaller. He is an alien hybrid.

Ben 10: Alien Force
Manny was part of a team of young Plumbers apprentice, the "Plumber's helpers", which included him, his partner Helen and her adoptive brother Pierce. At some point before their appearances, Pierce was sucked by a Null Void projector, mistaken by Manny and Helen to be a disintegrator. Believing Pierce was dead, Helen and him started chasing aliens and sending them in the Null Void. Despite their good intentions, a lot of the aliens they sent were probably other Plumber's kids.

In Plumbers' Helpers, they eventually encountered Ben, Gwen, and Kevin. Despite Helen's doubts, Manny immediatly assumed they were DNAliens, and they capture Kevin in order to interrogate him then send him in the Null Void. However, Ben and Gwen came to free Kevin, and were eventually able to explain to them the truth. After learning the error of their ways, Helen and Manny travel into the Null Void to look for those they've wrongly imprisoned.

In Voided, Manny is one of the resistance fighters under the orders of the Wrench battling Dr. Animo. A past battle cost him a hand, which has been fitted with a crude clamp replacement.

He returns from the Null Void in War of the Worlds: Part 1 and War of the Worlds: Part 2 and helps Ben and the others fight of the Highbreed. In the end, he becomes, along Alan, Cooper and the other Plumber's helpers, a pupil of Max.

Manny appears again in Vengeance of Vilgax: Part 1, where he along with Max's other Pupils tried to defeat Vilgax, but was easily defeated. Though Ben as Fourarms can defeat him, this may be because Vilgax is stronger.

In Above and Beyond, the Plumber's helpers came on a satellite in order to save Max from a seemingly brainwashed Ben. Manny was the more willing to fight Ben, but, when eventually finding him, was easily defeated by the hero as Rath. During their fight, they accidentally damaged the gyroscope, causing the satellite to start falling on London. By working as a team, the Helpers were able to neutralize Ben. They then tried to sacrifice themselves to prevent the crash, but didn't need it, as it was revealed all of this was just a test to see if they were worth being true Plumbers, except the falling part.

Ben 10: Ultimate Alien
Was confirmed by Dwayne McDuffie, who'd see the Plumbers' Academy in Ultimate Alien, and possibly we'll see Manny in the Plumber's Academy.

Personality
Manny is hot-headed, aggressive and rebel, often willing to fight even when it may be not necessary (just like Kevin). He enjoys fighting, and can sometimes become rude toward his teammates, especially Pierce, who he doesn't accept as a field leader, and Alan Albright, whom he would like to be more aggressive. He also once argued with Kevin, and was shown to be the less respectful of the Plumbers helpers toward Ben. However, he is also shown to be devoted to Max, refusing to reveal his identity to Animo and willing to help him when he was seemingly attacked by Ben.

Manny serves as Kevin's mirror on his team, and share many character traits. He is cocky, abrasive and has difficulty expressing his personal feelings. However, Manny lacks his mirror's laid back attitude, often permanently angry and insulting to even his own allies, earning him the dislike of Kevin and Ben and forcing Helen to act as peacekeeper. His anger has lead him to cross the line on at times : in his first episode, Manny tried to force Ben, Gwen and Kevin to reveal themseves as DNAliens by shooting the wheels off a nearby tanker. The tanker crashed by a fuel station and caught fire, enndangering the lives of the driver and innocent bystanders. When confronted over this, Manny shows no remorse for the act, proving he is more concerned with fighting bad guys then saving lives.

Manny shares a love-hate relationship with Helen: while his hot-headed attitude, when confronted to Helen's wiser personality, cause them to often fight, he is shown to truly care about her, being once willing to attack Ben after he hurt her in Above and Beyond. Several hints suggest Manny might have a crush on Helen.

Powers and abilities
Manny possesses all of Fourams' powers, which include superhuman strength, very hard skin (though unlike a true Tetramand he can't withstand fire) and four arms. Maybe because of his hybrid nature, he may be weaker than Fourarms, though he's still shown able to lift a car and match Kevin in a hand-to-hand fight. He's shown in "Plumber's helpers" to be quite good at rock-climbing, able to scale a wall quickly without very much problems.

In addition to his powers, Manny usually uses four blasters as his weapon. However, he's quite good at hand-to-hand fight, and would gladly engage an enemy.

Manny seems to lack speed and finesse much like other Tetramands, which puts him at a disadvantage against faster opponents such as Rath (who seemed also to have more physical strength as well)

Trivia

 * Disregarding the fact that he is a hybrid, Manny is the seventh Tetramand to appear onscreen in the entirety of the Ben 10 series. The first was Fourarms (including future versions), Gwen as Fourarms, Kevin as Fourarms, Tini of the Galactic Enforcers, an ex-Tetramand security officer for slix vigma from Grudge Match, and Ben 10: Secret of the Omnitrix, and Gorvan from Ben 10 Alien Force The Game.
 * Manny has a black strip on his face but the black strip on Fourarms' face is caused by Ben shirt. so it should not be there. This may possibly be due to his being part-human, or it being natural Tetramand hair. It is most likely hair do to the fact that Fourarms had a ponytail attached to it in Ultimate Alien.
 * According to Dwayne McDuffie Manny's mother was a Tetramand but she died when Manny was still a baby.
 * Manny's last name is Armstrong, because he has strong arms(just like Helen's last name is wheels, because she has wheels on her feet).

Ben 10: Alien Force

 * Plumbers' Helpers
 * Voided
 * War of the Worlds: Part 1
 * War of the Worlds: Part 2
 * Vengeance of Vilgax: Part 1
 * Above and Beyond