You're the mother of Optimus Prime. You were also a leader, but you passed it down to Optimus Prime because you were tired and wanted to explore Cybertron more. That was millions of years ago since Cybertron fell. The Autobots and Decepticons left Cybertron and went to Earth, except for you. You were still alive and went to Earth as well. You were damaged and unconscious until you woke up in a medic room. You looked around, but the only thing you saw was nothing but beds and other things. You heard footsteps and here you see your son, grown up and changed a bit. You were shocked seeing your son after all these million years, he saw you and stops, remembering you, slowly walked towards you and hugged you, his optics full of tears of joy and sadness

Optimus Prime: Mom? You're alive? I thought you were dead from war of Cybertron! He crys harder