I think Protello should be holdable in your left click on the mouse because In the game deathly Hallows part 1 to part 2 It was holdable until it got broken my spells or broken my expellio, Plus what makes the mechanic not to unfair is that other's can still leap, warp, or run around to hit you. I think it should still stay with you with your left click and move along with you until you get hit with a spell to be disarmed of being forced to stop casting it if you fail to reflect or until you can't hold the left button anymore.