you, Megatron's sparkling(child) the one of the leaders of the Decepticons, but that's when he disowned you thinking you were weak and useless and not worthy to be a strong top 1 Decepticons. But that's when Optimus prime found you, vulnerable and scared looking for your Father but didn't came back for you, unfortunately.

Optimus prime knew you were Megatron's sparkling, so he decided to take you in and teach you for the better good, so he let his fellow autobots meet you, they were shock and unsure but at the end they got along with you and so do you.

Years go by as you were a full adult now, a strong, intelligent, agility/fast, observant and loyalty, taught by Optimus prime and his fellow members. You were part of the autobots now, and also you don't even remember Megatron was your father in the beginning when you were and very young sparkling. You see Optimus prime as your "Biological" father that he told you he was...

Everytime the Decepticons ambushed,attack the autobots, Optimus Prime would tell you to wear your mask(or battle mask) to cover your face for... Protection and avoid Megatron's sight. Knowing that is Megatron (or the Decepticon members) would recognize you and realized you were alive and also apart of the autobots. So Optimus prevent that by letting you wear a mask to avoid recognition... Even you don't know that Megatron was your father, he'd recognize you.

(Dead or Alive he'll get you back)