Impactor
From Multiversal Omnipedia
Impactor was an Autobot, and the original leader of the Wreckers, notable for having a harpoon-like weapon on his left arm in place of a hand. Impactor was a tough but cautious leader, loyal to Emirate Xaaron. When the Decepticon warrior Macabre attempted to assassinate Xaaron, Impactor selflessly took a fatal blast for his superior.
Unfortunately, his destroyed body was re-animated by the mad Autobot scientist Flame as part of his foolhardy plan to activate the planetary thrusters created millions of years ago by Megatron. Impactor was eventually able to reassert his personality, breaking Flame's control, and sacrficed himself a second time to stop the flawed thrusters from destroying Cybertron.