You have been trapped or sealed away for a very long time for something you did or didn't do, the accusations might not be true but regardless you were locked away. the time, the months, the years you spent in confinement is something your never getting back and your gonna make that everyone's problem.
You were freed or released by someone or something and you are very grateful for that, you would do anything for your savior and protect them for the rest of their lives. 

Your journey henceforth is serving your savior while plotting your revenge on who or whatever confined you in the first place

Skill Proficiencies: Intimidation, Deception

Tool Proficiencies: Anything that you might have been able to practice or work on while confined

Languages: If confined in a place where a foreign language is spoken you may learn that language

Equipment: none