As it stands, this spell is kind of limited in use and rather weak, as it only works on "humanoids" which seems not to include stuff like werecreature mobs. The suggestion is that Heart Clutch should work on anything with a heart or other major internal organ to grab. So, anything except Undead, Oozes, Elementals and Vermin, pretty much.
That way, it becomes a characterful spell for a Necromancer to use vs pretty much any sort of foe. It wouldn't unbalance it for PVP as it makes no difference on PCs.