The Imperius virus is a brilliant idea, although the caster of the curse has to spend at least some mental energy giving directions to the victim, so there might be a limit to how many victims could be chained from the initial casting. A direct line seems to work just fine—there are canonical instances of Imperiused characters going on to place others under the curse—but I think a tree with many branches would not work.
The Imperius virus is a brilliant idea, although the caster of the curse has to spend at least some mental energy giving directions to the victim, so there might be a limit to how many victims could be chained from the initial casting. A direct line seems to work just fine—there are canonical instances of Imperiused characters going on to place others under the curse—but I think a tree with many branches would not work.