The filled right hand does not work with the shiftstone strap. The only time it works is when both hands are using the shifstone strap. But if I change the left hand to another armor peice, it does not work. The shiftstone strap always works with the filled left hand, even when the right hand is not a shiftstone strap. But the marking disappears as soon as I swap the left hand out of the shiftstone strap.