Sentinel Prime (IDW Comics)

Sentinel Prime, also known as Infinitus, was one of Optimus Prime's predecessors, who was the anti-heroic antagonist of Megatron Origin. He would return in the Titan's Return series as a fully fledged villain.

Titan's Return
to be added.

Trivia

 * Sentinel Prime's design is inspired by the Transformers Marvel Comics depiction of him.
 * Megatron Origin was the first time any Sentinel Prime was depicted as morally ambiguous, which would become a defining trait of the versions of the character, not least the live action movie version.