Jetfire

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. His bunny is dead on the wheel. 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.
He's 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 enough 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.