Ultimo

Ultimo is a large battle suit worn (and fused with physically and mentally) by Kearson DeWitt.

Biography
Ultimo was created by stealing and modifying an old version of J.A.R.V.I.S. and a project he was working on at Stark Industries, PROTEAN. Iron Man finally confronts the giant Ultimo and War Machine fights him while Iron Man fights the Kearson/Ultimo within. After removing the other Arc Reactors, War Machine and S.H.I.E.L.D. continue to attack while Iron Man fights the Kearson/Ultimo. In the end, Ultimo is destroyed when Nick Fury rams it with the S.H.I.E.L.D. Helicarrier.