When Optimus Prime died in the original Transformers series they brought him back to life in season 2 in an episode titled Dark Awakening. But it was soon discovered that he was only a zombie and his the 'soul' of Optimus Prime had passed on. It was only through great will power that his body able to break free from the evil spell. And I don't know about you, but I'm no Optimus Prime. I'm afraid my body wouldn't have the will to resist being an evil cunt without my soul to there to direct it. Maybe Someone as strong a leader as Optimus prime can --but I don't want to take that kind of risk with cryogenics.(Edited 1 minute later.)