Optimus Prime

Optimus Prime is the main character of Transformers: Prime and the official leader of the Autobots during the war on Cybertron, as well as the leader of Team Prime. Before the Great War, Optimus Prime was originally known as Orion Pax; a young data clerk who worked in Iacon, under the wing of Alpha Trion. Alpha Trion was a mentor to Orion Pax and believed in Orion to become the next Prime. Orion Pax was chosen by the High Council and became "Optimus Prime," upon being entrusted with the Matrix of Leadership by Primus himself. Years of war against his old friend/rival, Megatron, have brought Optimus and his team to Earth.

Personality
When Optimus was originally known as Orion Pax, who was very timid and constantly doubted himself at times. Despite this, Orion proved himself to be a capable leader countless times. When Optimus returned to his original form briefly on Earth, he maintained much of the same idealistic traits as he did before his transformation into a Prime. However, one thing Orion continued to possess was his sense of right and wrong. This led Orion to discover Megatron's plan to use his research for evil and to destroy the peaceful Autobots, who Megatron claimed were evil. Unfortunately, Orion's senses of goodness and honor also made him easily manipulated, as seen by his dedication toward assisting Megatron beforehand. Above all, Orion knew his place was with the Autobots and not with the Decepticons.

As Optimus Prime, he is a very stern and serious leader, not taking jokes, and as Bulkhead described, never crying out or losing his cool. But when Optimus does lose his cool, it is due to the Decepticons who irritate him the most. This was shown when Starscream had stolen the three Omega Keys from the Autobot base, which left Optimus to rage towards the sky when Starscream escaped with the keys. Optimus is shown to not be the party type either, but he would attend little ceremonies. It is currently unknown if Optimus can dance or likes to listen to music like Bulkhead, Wheeljack, and Bumblebee can.

Optimus can also be at the same time a very caring bot, making sacrifices to ensure the safety of the team and their human allies, even he would go as far as to sacrifice himself to save them, Earth, and Cybertron. Optimus also has a strong sense of honor and loyalty. However, Optimus has been shown willing enough to leave his code of honor and resort to Decepticon tactics in order to stop Megatron. The tasks of protecting humans and stopping the Decepticons simultaneously should have brought him to his knees, however he did not give up. Optimus would even risk his spark to change a decepticon to side with the Autobots, including Dreadwing, Skyquake, and Breakdown.