ok so this is what u need to do, have done it on iceblood tower a few times today, run up not stealthed jump up on barrels, cap the tower. jump up on the shield with the 2 spears and vanish. if the mobs only had u targeted and no one else is near or in tower they will "vanish" dunno if its an exploit, got no screens so "it didnt happn" try it out for ur self and see what u think
remember only u at tower and only u targeted from mobs