Master Control

The Master Control was a program found in the Omnitrix and confirmed by Dwayne McDuffie, in the Ultimatrix. It adds greats powers like access to aliens in Ben 10: Alien Force, and instant changes and unlimited timing in Back With a Vengeance. It is unlocked by a special code when not activated.

Ben 10
The Master Control first appeared in the episode Back with a Vengeance. Ben unlocks it by accident when on a boat trip. When a man falls of the boat, he uses Ripjaws to get him out of the water and Stinklfy to fly on back to the boat. He then stays Stinkfly for hours (Showing off his unlimited timing ) and ruins Gwen's ice cream, who is extremely annoyed by his new powers. After this, he ruins some pictures and causes more trouble until Vilgax and Kevin 11 come to steal the Omnitrix, until grandpa Max sends them into the Null Void with Ben as Diamondhead. After a long chase, they finally get the Omnitrix until Gwen tricks them and get them back. But Ben, who turned off the Master Control, accidently transforms into Grey Matter and tries to turn back but fails. After this, the Master Control never appeared again.

Ben 10: Alien Force
The Master Control reappears when Azmuth inputs the code to grand Ben new aliens such as Upchuck, Way Big and Cannonbolt in War of the Worlds. After this, he uses the aliens through out the series to fight enemies.

Ben 10: Ultimate Alien
Dwayne McDuffie confirmed that the Ultimatrix also has the Master Control. It us currently unknown if it unlocks more aliens or the powers from the original series.