Sentinel Prime - Transformers: Dark of The Moon

In the Transformers film series, Sentinel Prime is a legendary warrior thought to have been lost long ago. He once led an expedition that took him fourteen galactic convergences to get an echo of something. Sentinel Prime is Optimus Prime's direct predecessor, mentor, and father figure. Sentinel's weapons include a shield, a double-bladed Primax Blade sword that can be folded into one, and a cosmic rust cannon that causes any metal object that it hits to rust into oblivion, as evidenced in the third movie when he shoots Ironhide once in the chest and twice in the back. His intention is to restore Cybertron to its former glory after the war, driven by desperation he turned him against his ideals by siding with the Decepticons. Sentinel Prime is voiced by Leonard Nimoy, who previously voiced the character Galvatron in The Transformers: The Movie.