There is bloodstar or something like that in SpC that drains 1 point of con every time you hit the designated creature. As I recall it's considered a horrible spell, but it's there.
No no, it's not horrible.
Not with the proper setup.
Just toss summons with a lot of attacks onto the target.
Your party totemist for the same reason.
Your archery buddy with his splitting bow.
Your snap kick flurry-of-blowing monk friend.
....that sounds not quite right.
Anyway, you get the point.