User blog comment:MisterRandom2/Can an Angel Blade kill a demon?/@comment-1509826-20120606191650

I very much doubt it, firstly the fact that it can kill a higher being doesn't mean it can kill a lower being, ruby's knife can kill all but the highest demons, but it can't kill anything else, phenonix ash can kill eve, the mother of all monsters, but its harmless to everything else. Its not a rule that just cause it can kill a higher being it can kill a lower being.

Secondly, on screen evidence sugests it can't, in Reading is fundermental, to kill the demons tailing them, Meg steals the knife, or as she puts it "borrows" but she already had aquired an angel blade, if the blade could kill it, why take the knife? And if it was just as a precation against something else, why use it? An angel blade is longer and much easier to kill with.