Omnimaster is a Galvanic Magister from the planet Glavic in Ben 10: Master Control. Like the Galvanic Mechmorph, Omnimaster's species is a creation of the Galvans. Galvanic Magisters seem to have a hatred of the color red
He has six eyes and a green and black armor filled with DNA from Primus. He will flicker red as the Omnitrix starts to time out. His Omnitrix symbol is larger than most other aliens.
Omnimasters powers are the ability to use any Omnitrix feature while in alien form. He can also use the powers of other aliens like fire balls, flying, eye layers, diamond shooting, and super-speed but at a smaller degree.
Ben has a problem using Omnimaster because after he does the omnitrix has to recharge for a while. Ben needs to be careful with what power he uses if that alien has problems it gets that problem. He will time out if trying to use 's abilities. He will need sometime to master a new aliens abilities an can sometimes go out of control.
If Omnimaster is accessed through the ultimatrix or another evolution using device he can become Ultimaster, whose power is even greater then his own.