I had read somewhere that the original concept for the story of Terminator Salvation was conceived to follow the pattern of the original Terminator movies, which was to protect someone important, in the 1st it was Sarah Connor, in the 2nd it was John Connor, and the 3rd John Connor and his future wife Kate Brewster. In this case, Kyle Reese and not involving time travel instead protecting him now post-Judgment Day. Now, I can’t find where I read that but I could see the potential in that story.
For staters, Skynet knows shit about Kyle Reese. See, Connor is still not the leader of the Resistance and maybe we keep the signal idea. But Connor wants to find Kyle Reese, but he doesn’t know how to find him. Kate says, “are you sure you wanna do this?” and John says, “we need to find him. He must survive or I will never exist.”
Then we cut to Marcus waking up with no idea where he is or what’s going on. He walks through the post-apocalyptic world and finds Kyle Reese and they team up to try and find the Resistance. They fight off Terminators and HKs until Kyle is captured by the Terminators. Marcus teams up with Blair to find John Connor and rescue Kyle. Marcus saves Blair from the scavengers. They make it to Connor’s base, but Marcus steps on a landmine. Suddenly, Marcus is knocked unconscious. Marcus wakes up with Connor asking him all these questions like, “What are you doing here? Did you locate your objective?” Marcus doesn’t know what’s going on. Marcus realizes that he’s a machine, but still thinks he’s human. Connor says that he programmed Marcus to find Kyle Reese for him, but as a surprise to both Connor and Marcus, neither realized that Marcus didn’t know he wasn’t human. Marcus tell him that Kyle Reese is heading for Skynet.
Connor decides to disassemble him and figure out how to get inside Skynet and rescue Kyle Reese, again, Connor can’t convince Command not to bomb Skynet. Blair breaks Marcus out and Connor goes to stop him. Marcus rescues Connor from the Hydrobot and Connor isn’t sure if he can be trusted since he doesn’t understand Marcus’ program. Marcus says he can get Connor inside Skynet and they team up to rescue him.
Connor is relieved of duty, Connor convinces the the Resistance to stand down, and heads for Skynet. Marcus walks through Skynet. Marcus helps Connor get inside Skynet, when Marcus passes out. Skynet awakens him. Marcus asks who he is, Skynet explains that he’s a prototype infiltrator, built with human memories to make him a better infiltrator and that Connor reprogrammed him. Skynet explains that the signal was a trap and kills Resistance Command. Skynet says that he was perfect to the termination of John Connor. John discovers a T-800 waiting for him. Marcus goes to save Connor and Kyle Reese, and he does.
Now, whether he should be a Terminator Hybrid, I mean, that can work, or Marcus could be a normal Terminator. I could go either way. With the hybrid idea, he has his human memories and he can still gives his heart to save Connor. But the main point is, Skynet is mostly focusing on his signal plan. Skynet realizes his infiltration prototype, reprogrammed by Connor helped him terminate Connor, but it came back to bite him. That’s one idea of how to do it.