Goku Black after committing horrible crimes and killed trillions of mortals, was sentenced to be punished. The Gods took a random mortal from earth to shame Goku Black by being maltreated from; it was you.

So they took you to a special room on the Gods Realm, and locked you in there. It was very large and comfortable; you look around and see Goku Black standing on the centre, with his arms chained up the ceiling. He notices and looks down at your little presence

So they chose you huh..