Well, this story is settled in the IDW universe, right after Sunstreaker was fully repaired in the CR chambers, and his mind belonged to him alone again. The dialogue between the two humans DOES NOT BELONG TO ME, it's a part of IDW All Hail Megatron, volume 14. I just… borrowed it. Obviously, any of this characters belong to me either, I'm just playing with them.

And there he was again, sitting in that cold berth placed against one of the walls of the Med Bay. He didn't even know for how long he was supposed to stay there, just like every other time he had been in the infirmary. But this time it was different. This time his mind was different. He had too much time to think and he wasn't enjoying it. His mind kept going back to the time he was being held captive, disassembled, decapitated, and barely alive. However, alive enough to know and feel everything they were doing to him.

-Flashback-

Pain. Pain was all he felt. His processor was slightly numb, but not enough to protect him from the extreme pain he was going through. He onlined his optics, but immediately wished he hadn't. He was tied to a huge table, connected to monitors and surrounded by humans. They were looking at him curiously, interrupting their activities to stare at him in awe.

It was in that moment when he realized what they carried in their hands. Saws, screwdrivers and many other tools that he didn't know what they were used for. But he understood in the exact moment in which they resumed their activities and continued to disassemble him alive. They were tearing him apart, cutting his body to pieces, and he was feeling it all, unable to do anything to stop them. He let out a pained, feral scream, the only thing he could do at the moment, and struggled in vane to break free. He felt how the electric saws cut their way through his derma-plating and the sensitive wires below, shredding them in the most painful way possible. They were everywhere; his servos, his chassis, his neck… only his head remained untouched.

Oblivious to him, on the other side of the room, one of the humans was speaking to his superior, covering his ears with a pained expression in his face. But the pain was his own, and sympathy had no place in his mind.

"Well, there's got to be some way to shut it up! The noise is unbearable!" the human said.

"What do you suggest? Anesthetics? It's a machine!" His superior's voice came through the speakers of the computer.

"Why don't we take it offline somehow?" the man suggested, still thinking of his own comfort rather than Sunstreaker's suffering.

"And miss out on all this data? I don't think so." The other man replied coldly. "I want all the readings we can get on these things. It's a machine, Douglas. A piece of metal. It's not like it can feel pain like we do. It's an automated response."

"I don't care about that! It's just distracting!"

"Then get yourself some earplugs and get on with it". And the communication was over.

But… they were wrong.

-End of flashback-

He sunk in the berth shaking his helm, a frown settling in his faceplates. He shouldn't be thinking about it. He was supposed to be offline. He had asked Hunter to offline him, and the human had refused. If only he knew…. If only he had any idea about the feelings of dread and filth that were now fixed in his processor, he would have decided otherwise. Now it was too late. He was alive. "Alive". Such a meaningless word to him now. He felt disgusted with himself every time he thought about what they did to him. How they used his mind, his processor, to control the headmasters. How the humans penetrated his mind, went through every wire and memory he had, tainting it with their own, leaving fingerprints of what they were. Changing him and what he was, forever.

"You are different now, Sunstreaker. You are not what you used to be." His brother said once. He had laughed bitterly at those words, trying to convince him that he was fine… that he was still the same. Empty words came out of his mouth. Of course he was not the same. His mind had been merged with those of the humans, with Hunter's, he was tainted, dirty… and now that he thought about it, now that he took his time to consider every little detail, he knew he would never be the same. He would never go back to be the proud warrior he used to be.

He had to leave. He couldn't stand that despicable planet anymore. Everything in it made him go back to that time when he was tortured, when his mind was violated. That was the moment in which he made the decision. No matter how hard it could be, or what he had to do, he would leave Earth and give the humans what they deserved. He was going to make them pay.