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, cosmic rust gun and a double-bladed sword that can be folded into one. His intention to restore Cybertron to its former glory after the war drove him mad and going against his ideals by siding with the Decepticons. He transforms into a Rosenbauer Panther fire truck.