Sentinel Prime

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. His intention to restore Cybertron to its former glory after the war drove him mad and going against his ideals by siding with the Deceptions.

In Transformers: Revenge of the Fallen, Sentinel Prime is briefly mentioned in the rambling speech given by Sam Witwicky while under an All Spark fragment-induced trance, with Sam mentioning a "mission". Sentinel Prime appears in Transformers: Dark of the Moon as one of the main antagonist alongside Shockwave, [8] revealed to have left Cybertron near the end of the war. Though it was believed that the Space Bridge technology he devised was to turn the tide of the war, Sentinel Prime actually sided with Megatron to rebuild Cybertron by finding an inhabitable world and enslave its occupants. However, the Ark, Sentinel's ship was hit and it eventually crashed on Earth's moon in 1961.Later after maintaining a vehicle mode Sentinal explores the planet with Optimus and finds it peaceful unlike the last day of Cybertron. Optimus offers to lend Sentinal back his possision as leader along with the Matrix but Sentinal denys it and tells him to keep them both. Eventually, once Sam goes against Charotte Mearing's orders to stop helping Sentinel betrays to Autobots, for he was revealed to going with Megatron for Decepticon and he kills Ironhide with his acid-rust blaster to prove why the decepticons know about the pillars and destroys much of NEST HQ' in rage, before getting the pillars to DC and summoning a Decepticon Armada. Though Optimus tries to stop him, from opening the space bridge, Sentinel almost kills him, but stops, saying that he's lucky he didn't kill him. Soon after, Sentinel Prime takes command over the Decepticons as Nemisis Prime and oversees the final phase of the plan in Chicago before Optimus stopped him from bringing Cybertron all the way through which makes Nemisis very angry as he engages the autobots and NEST. His body armor was to thick for the human saborounds to penatreat and he unfairly cuts off Optimus' right arm and ignorantly tries to kill him but Megatron intervenes in his fight with Optimus Prime by blasting him hard with his shotgun that contains the only fire power dense enough to penatrate him and then the decepticon leader pulverizes nemesis and weakens him. Optimus then kills Megatron. Before killing his former mentor and father, Nemisis, now back to being Sentinel asks Prime if he now understands why he had to betray him, and Optimus claims " You didn't betray me, you betrayed yourself." and then shoots him with Megatron's cannon, killing him for betraying his position as an autobot and the human race over his obsession with Cybertron. At some point in the film, he claims to Megatron, even though he aided him in opening the space bridge, he will never serve him.

Voice Actor

 * Leonard Nimoy