In his day, Jetfire was a living legend both in the air and on the battlefield. Sadly, his day has long since passed. His body went south years back. He's got rust in places he didn't even know he had. Basically, Jetfire's old! An ancient Decepticon Seeker, Jetfire was around long before the war broke out, and unlike many, came to see his "comrades" for what they were. This caused him to defect to the Autobots, something virtually unheard of. As a consequence, Jetfire never managed to fully obtain the trust of the others back in the day.
Jetfire is still a fine asset, powerful and able to activate a space bridge to teleport across great distances. This is slightly offset by the fact he's so old. After years without a proper source of energon, he's practically falling apart. His processor gave up the ghost millennia ago. These days he has a hard time remembering his name, and he's lucky if his teleporting puts him on the right planet. It makes him a bit crotchety and also leaves him with the nagging feeling he's forgotten something important. His alternate mode is that of an SR-71 Blackbird spy plane.
During the final battle around the Great Pyramid of Giza (which contained the Star Harvester), Jetfire arrived and attempted to "stick" the landing, which didn't go quite as he planned. He immediately decided to "show how they brought the pain in my day", using his axe to slice Mixmaster across the chest and decapitate the Constructicon. He was critically wounded by a surprise attack from Scorponok and although he managed to crush the Decepticon's head, the injury was fatal. Fortunately, Jetfire was treated to one last wonder, as Sam Witwicky used the Matrix to resurrect Optimus. Jetfire was overjoyed of the moment, hardly believing that he was seeing a living Prime.
Unfortunately, The Fallen teleported in and attacked, damaging Optimus and stealing the Matrix, placing it in the harvester. As he lay dying, Jetfire, who felt that during his entire life he'd never done a thing worth doing, offered his parts to Optimus Prime, saying that they would give him "a power like you've never known". Telling Optimus to fulfill his destiny, Jetfire ripped out his spark core and died.
Jetfire's sacrifice was not in vain: within moments of his death, Ratchet instructed Jolt to begin a full transplant of the afterburners and weapons systems onto Optimus. Now equipped with Jetfire's powerful weapons and engines, Optimus broke through a blockade of debris The Fallen had telekinetically erected around the Pyramid and destroyed the Star Harvester before it could be used against the Earth's Sun. Prime then faced the Fallen and Megatron, using his afterburners to send Megatron flying through some ruins. During the battle, The Fallen pulled off the left wing and afterburner, using them to strike Prime in the face, but Optimus ultimately triumphed and ripped out the Fallen's spark core, killing the treacherous Prime. After the battle, Optimus quickly detached Jetfire's parts.
