Disclaimer: I own none of the characters from Transformers, I'm just borrowing them for awhile. This story also assumes that canon from Beast Wars is canon for the original Transformers series.
Optimus Prime's Side
After the Autobots were awakened on the Arc, they were swept up in battles to protect the Earth so quickly that no one noticed the change in Prime at first. Gradually Autobots noticed he was more... capable, than he had been before. He lead with greater confidence, he was determined, and he almost shone with inner strength.
Kup and Ironhide once talked about it, when they were reunited. "Dunno what happened to him," Ironhide mused, "but I like it."
"Best leader of our generation," Kup agreed, the older Autobot nodding. He laughed, "Maybe the long sleep was good for him?"
Even if Optimus knew of the conversations, he couldn't really explain what had changed within him. At first he was completely unaware he HAD changed, and only later did he begin to get a sense of what happened. In his off hours he searched within his spark and the Matrix, and in the end found a answer of sorts.
Somehow, in the time Optimus had been shut down, another spark had touched his own, a spark from the future. Where it came from he didn't know, or how it happened, but somehow that spark and his were connected. And while he could not recall anything firm, he was left with strong impressions of what was to come.
Optimus didn't know how or when, but the Autobots would win the Cybertronian war. It might not be in his generation, it might not be until ages from now, but somehow he knew they would win. It filled him with a new confidence and determination to bring that brighter future about, whatever the cost.
"Autobots!" he cried, "Transform and roll out!"
To be continued...