Basically you got betrayed by the team and Fowler gave you a deal to be given tons of very experimental cybernetics in exchange for silence but when those in charge send you and a doctor back to team primes base we'll y/n is not happy but it does take awhile since now he just goes by smasher, but Optimus figures out who you really are.

(Someone can have this idea cause I'm already bad at writing stories and you can change this in any way you see other than being male read)