by Syvanis
I am guessing here.Thematically, I think you would go with the Original would get first pick since the mimic is just copying the other. Plus, Mimic shouldn't be able to stop someone else's power from working which is what it would do in this place.
Mechanically, I would say: If it is your turn you get to pick first. Then if it is not either players turn go with the next in line that has the ability.