Some would say that this is Bumblebee. That is partially true. It was not until many years after his arrival on Earth that the Maximal Centurion learned that he had been tricked into taking another’s identity. During that time, he had fought what seemed to be the Decepticons, defending Earth and the humans. However, he found that he was fighting others like himself, Maximals who believed themselves to be other well-known Cybertronians. This led to him hunting down and killing the others, believing them to be too much of a threat to Earth. He later was forced to stop when the real Autobots and Decepticons arrived, leading him to briefly join forces with the US military to fight against the Decepticon forces. Eventually, Centurion left, believing that the war could only be stopped once both sides left Earth.
(Biography based on this wiki article )
This is my redesign of Centurion in the style of the new movies. His official design is pretty similar to Bumblebee’s 2018 reboot design, so it was easier to modify. His vehicle mode in this sketch is a steam engine with a jackhammer for tunnel-boring.