At my PC "KB The Legend" is not installed now, I played it only once and don't remember all spells. So there are two discriptions more. May be the question was about one of them.
exorcism.jpg EXORCISM from magic of light. Makes damage to demons and undead (200 400 and 600 at different levels), and doubled damage to phantoms and summoned creatures. It costs 10, 20 and 30 of mana.
pestis.jpg PESTIS from magic of chaos. Reduces base level of atack, defence and health (-15%, -20% and -25%. It costs 5, 15 and 20 of mana). Demons, plants and golems are resistable. Undead under pestis have increased moral and none of negative effects.