I agree with Mr. Prvoerbius. I am an elf with a harm spell. I use it only once with the Ailing Wolves and they end up dead.
Best low level spell... Disarm, for enemies with weapons... Just disarm them and beat them to death with your staff. :smile: Yes, I know this is not what you meant, but Harm was already chosen. Heheh...
Disintegrate is not a low level spell but it is a great offensive spell together with quenching life.