"Expect death. It is coming, and I am waiting."
Killfire is an invention of Unicron's that has one purpose and programming: destruction. He is very edgy about talking about his origins and may or may not be evil. He has a one-track mind bent on the destruction of Cybertron and Earth, and is occasionally allied with the Decepticons. He has a seeping hatred for Optimus Prime and argues with Megatron about who is more worthy of kiling him. He was once Ironhide's closest friend.
First Million Years
Not long after being forged alongside the first Decepticon leader in the belly of Unicron, Killfire was sent to destroy pre-historic earth. There, Killfire took up his name of Killfire as he killed every life-form in sight, setting entire parts of Pangea on fire.
Second Million Years
Killfire had, after his first million years come to contact his father about destroying Cybertron, after destroying every life-form he saw. He was sent into space alone, on his own to destroy entire stars and planets he saw with his powerful ion blasters. His one-track killer instinct mind and lust for carnage and destruction brought him to destroy countless planets from far off, honing his targeting skills as well as fighting.
Third Million Years
Soon, Killfire discovered Cybertron, the planet he was sent to utterly obliterate, after two million years of space travel.
When he landed at a dock in the city called Iacon, Killfire met a peculiar robot, one with the ability to transform into an incredible machine. His name was Orion Pax. Just when Killfire was about to ion blast him, another bot did, this one far larger and more powerful.
"A great warrior, easily my equal."
Killfire was shocked to see the stature of this bot, shining silver with the moon. He was easily an equal to Killfire, standing tall and proud.
Rampage On Cybertron
But standing still for so long was getting to Killfire. He had to kill something. He looked at the tall warrior. He aimed his ion discharger at him. The blast only phased the robot, who turned and angrily yelled, "No one dares fire a laser at the great MEGATRON!!" And Megatron blasted Killfire, who did not have much endurance expereance, automatically was sent to stasis. He was taken to a Cybertronian phycisist named Alpha Trion, who rebuilt Killfire into a robot named Hot Shot. (Follow the link for Killfire's life as Hot Shot and read it until it states Kilfire was released, then get your skidplate over here.)
Transforming your day into a wicked grin is a big job
Killfire rampaged across Cybertron until he found Shockwave, and he ripped him apart until he found his transformer chip and inserted it in himself, and he forced a bot named Ultra Magnus to find an alternate mode for him and then to make Alpha 4 (a supercomputer) scan it and download it into him. He transformed for the first time.
Killfire was tall and powerful, armed with many blaster cannons and had blazing red-orange optical sensors. His had was spiked and neckless, and very frightening by both human and Cybertronian standards. He was very strong. Without his lust for violence, carnage and destruction and with another track added to his mind he would make a good Autobot.