ok so i'm sorry but there is one flaw in the pervaders. The Mein is well if it's meant to prevent one from harming/killing others or even just other pervaders then well they would have to either come to a compromise to get the dagger or give it to Alen to study.
nah. They can attack each other. But if with intent to kill then it becomes a problem. Now while not giving them the dagger is not with the intent to kill, knowing they can kill those afflicted is well = to knowing you're killing them thus same as intent. It's not the same as accidentally killing someone as they had no intent on killing and didn't even know it'd kill.