It carries a fairly hefty amount of enmity with it as well (320CE/320VE I think, total of 640 enmity), and I doubt it'll be particularly accurate on anything worth fighting, since I'm pretty sure it works off of Blue Magic skill and MACC. Casting it 3-4 (or more) times trying to get it to stick may leave you with more enmity than you'd want, if you're working with a charmed pet.