I got many transformers and for each of them I wrote a bio and I wondered about sharing them (but yeah, if I got flamed I'll end it quickly). Here is the first. I put pics from a respected site because they are way better than mine (but in the case of Optimus Prime, I don't have Leobreaker to make the Savage claw mode).
Optimus Prime / Orion Pax Optimus Prime is the awe-inspiring leader of the Autobot forces. He turns into a big, red truck. Originally a civilian, he was chosen by the Matrix to command, the first in a number of heavy burdens he has been forced to bear. Another is his bringing of the Transformers' conflict to Earth. The complete opposite of his mortal enemy Megatron, every casualty, human or Cybertronian, weighs heavily on his spark. He does not show this side to his soldiers, and he never succumbs to despair. The Autobots need a decisive, charismatic leader, and that is what he gives them. It was that leadership which turned the tide of the Great War. On the battlefield, there are few who rival Optimus Prime's prowess. His ion blaster and his energon-axe are deadly weapons, though lacking when compared to others. He is easily the strongest of any Autobot his size, and what he lacks in raw firepower he easily compensates with guts. He would sacrifice his life to protect his fellow Autobots or those under their care, and has on a few occasions. His compassion for other sentient beings is his only real weakness, and one the Decepticons have taken advantage of time and again... though it's also the source of his strength! His motto is Freedom is the right of every sentient being. Optimus Prime started as Orion Pax, a civilian librarian who never fought and believed in peace. He was surprised to be designed by the Matrix to be the new leader of the Guardians of Cybercity, who became under his leadership the Autobots, when Sentinel Prime died in battle with Megatron. He then trained with Treadbolt, Landmine and Kup to become the heroic leader and great tactician he is now. He has a romance with Elita-1. His brothers are Ultra Magnus (older) and Optionix / Optimus Primal (younger). - He has a small remote-controlled robot named Roller who lives in his trailer. He was formerly a work drone known as Barrelroller. - He can combine with the Nebulan scientist Hi-Q to be a powermaster, granting him additionnal power. - Transformation of the trailer into a base. The base has a powerful firepower, equipement, and has a shuttle. - Can combine with his trailer for Super Optimus Prime mode. It grants him more firepower, strength and armor. His trailer is known as an Apex Armor. - He is the Matrix bearer. That offers a lot of advantages! - His trailer can turn into a remote-controlled robot named Apex Bomber. He has flying ability, firepower and transport abilities. - He has an Energon axe that has a power-axe mode and can turn into an hallebard. - Can combine with Ultra Magnus for Omega Prime mode. Increase his strength, endurance, armor and firepower. - Can combine with Jetfire for Jet Optimus mode. Grant him firepower, speed and space fly ability. - Can combine with the robot Overload and his pilot minicon Roll-out. The fusion can be with the robot or the trailer when in his base mode. That increases his firepower by a really big amount. - Minicons partners : Sparkplug and Over-run. As most minicons fusion, it increase all the physical abilities of Optimus Prime. - Powerlinx mode by crystal of combinaison : it allows Optimus Prime to combine with 4 small half-scientent modules that are dead transformers. They can take the place of arms and feet in any combinaison. Op-1 module : firetruck, 2 : copter, 3 : driller, 4 : submarine - Can combine with Omega Supreme for Powerlink Omega supreme. Grant him space fly ability, firepower, speed, armor, strength, endurance and more... - Can combine with Wingsaber or his brother Wingblade for sonic wing mode. Flying ability and speed, with a bit of melee and firepower bonus. - Matrix cyber-key for more power. Increase his firepower. - Savage claw mode with Leobreaker. This mode replaces one of his arm, and can be granted even more power with a Jungle planet cyber-key. It grants speed, strength and melee. - Special firetruck mode giving firepower and flying ability.