So I mean the illusion will attack all nearby units it self and cannot be controled by player to attack specific unit.. And if I use like what u said I afraid the illusion can be used as an immortal tanker .What do you mean 'uncontrollable'? To make an invulnerable image, just use the ability 'item illusions' and set damage received to 0.
that is, trigger hero action >>> hero - order hero to use last created item on unitUrm, what is the trigger order for the dummy to cast the Wand of Illusion on you?