1. It's a one-round-lag spell. Vamp is 2, pwk 3 I think.
2. He was unsanced, so I knew if I could get my truckload of undead meat to beat on him he'd be dead or wimpy after 1 round (see 1.)
3. It does *decent* damage and relatively consistently. Maims is about the low end you'd usually see with it. Chill touch will sometimes do "injures", sometimes MASSACRES (or higher).

I didn't really do it for any other reason than to cause damage with a 1 round spell. Chill touch would have worked fine too, but I had an alias for ghoulish numbing.

Oh and as for energy drain since he was sleeping if he saved against it he'd still be sleeping and I'd be lagged for a round with no undead beating on him.