I noticed you added this after my reply.
theory 1. if when you turn left the, left "rudervator" goes up and the right one down the plane in theory would bank left. But then when the plane is banked over the right flap is then vertical (like a rudder) but it is faceing the wrong way and would try to make the plane turn right even when its banked left.
theory 2. if when you turn left the left "rudervator" goes down this would act like an elavator and would turn that side of the plane down and the other "rudervater" would turn its side of the plane up so the plane would bank over.
You seem to be a tad confused about this Matt but that's not uncommon. Assuming it's a rudder/elevator model without ailerons the same principles apply as for a conventional rudder & elevator model. The rudder controls yaw & the elevators control pitch. The fact it's a V-tail makes no difference. The bank (roll) is induced by the yaw & has nothing to do with the ruddervators themselves. (This is the reason most rudder/elevator models have a greater wing dihedral than those with ailerons. If you're an experienced modeller you should know the theory.)
As I said before, turning left involves left rudder - yawing the nose to the left (or the tail to the right). Looking forward from the rear of the model, to yaw the nose left (left rudder) the left ruddervator goes "down" & the right ruddervator goes "up". In fact they're both moving left on the rudder axis. Moving in "opposite" directions on the elevator axis cancels out any change in pitch. If you rotate the model as I suggested you will be able to see this more clearly.