SevenSeven

Sevenseven is another Sotoraggian villain, in the second and third series, Ben 10 Alien Force and Ben 10 Ultimate Alien, first appearing in X = Ben + 2, an alien force episode. It is stated that he is of the same species as Sixsix, but "11 more dangerous". Like his younger brother Sixsix, he does not speak English, even if he's talking to aliens who do, but they are shown to understand him. In an extended episode of the first series, Ben 10, it is mentioned that Sevenseven is Sixsix's older brother, although Sevenseven isn't genetically mutated like Sixsix is, he has dark Grey skin and black-and-white eyes, not light Grey skin and robotic eyes, like Sixsix, like a non-mutant Android, but he was experimented on, because he had nano-robots infused into his hands so they could transform them into weapons, like some Androids do. He can transform both of his hands into cannons that fire laser discs, energy beams, and laser machine gun bullets, and a buzz-saw, and has wire cannons that fire laser discs and machine gun lasers, discs, turrets that fire lasers and energy saws, and homing heat-seeking missiles, grenades, and short-range flash-bang grenades.

Alien Force
In the Alien Force episode X = Ben + 2, Sevenseven kidnaps Attea, daughter of the Incursion emperor Milleous, and holding her for ransom. When the ransom is paid however, Attea offers him twice as much to help her overthrow her father. During a fight with Swampfire, Sevenseven helmet is damaged, forcing him to retreat.

Ultimate Alien
He reappeared, after a long time, in the Ultimate Alien episode, Hit 'Em Where They Live, teaming up with Zombozo the clown, Charmcaster the magician, and Vulkanus, the bounty hunter to take revenge on Ben, for their defeat, by killing his Mom, kidnapping his Dad and Gwen and killing Max. He is seen targeting Sandra Tennyson but fights Max Tennyson instead when he shows up and flies away when Max sticks a knife into his jetpack, making it malfunction. He makes his second appearance in the episode The Big Story, he was fighting Gwen, Kevin and Rath. He ends up being tied up and is left there.

Alien Force

 * X = Ben + 2Sevenstory.jpg"]]

Ultimate Alien

 * Hit 'Em Where They Live
 * The Big Story

Video Game
Sevenseven appears in the video game Ben 10 Ultimate Alien: Cosmic Destruction on the Devil's Tower level, part 2. He is one of the bounty hunters hired by the Evil Way Big on Earth who are hired to take the Potis Altiare, an alien artifact created by Azmuth's ancestors that can upgrade the Ultimatrix. After an attempt to defeat Ben by shooting him, he fights Ben himself but is easily defeated, but he escapes.

Trivia

 * Sixsix has his name from the missile launchers on his wrists, with six small missiles; Sevenseven could have the same reason.