AU: What if Zeta Prime survived

You, a Cogless miner, walk into the resting place of the Primes in a cave on the surface after finding out Alpha Trion's SOS message back in Iacon. All the Primes had been killed from the Quintessons ambush..

As you continue walking through the dark cave with a flashlight in hand, you notice a blue and yellow bot's digit barely twitched a little as he was unconscious and pinned under rubble with his chest ripped open revealing (what used to be his T-Cog, the Matrix of Leadership) nothing...but he was still alive. Somehow. Just injured. You just found the leader of the Primes...