Jetfire had left Cybertron centuries ago looking for some way to heal their planet, unaware of the current war, he finds and reactivates the dormant Autobots and Decepticons and they resume their war. realizing what's he's done after he wakes up Starscream and he starts killing sleeping autobots, Jetfire sides with Optimus and try's to save the other autobots, as a result he dies thinking that he failed everyone. (although in later issues he is brought back, but not exactly how he once was...)