Mimiron, or really big mechagnome as I like to call him, is the creator... of things. He basically designed most of the ulduar defense systems and is the "father" of the gnome race. V-07-TR-0N is this ultimate creation, but after the anti-super hero laws passed in the 70's he retired his suit and turned to a cooperate life. He started the Pyramid company and with the help of Algalon he has eliminated our dependence on fossil fuels, he has also made millions from his toy line featuring the watchers. Mimiron is indeed the smartest gnome on Azeroth.
The fight is split into 4 phases, first another flame leviathan then a anti-personnel cannon, then the bowser flying head. The fourth phase he combines them together to make Voltron!--err V-07-TR-0N. During this phase you'll need to kill all the parts at the same time (within 10 secs of each other) this will prob be a bit more difficult on 10man since you'll only have 5 dps.