ToME: the Tales of Maj'Eyal

I think spellcasting NPCs shouldn't randomly spawn with stuff powered by arcane-disrupting forces. It's just not worth it for them, especially the ones that rely heavily on spells. I ran into a worm that walks that did nothing but fail to cast Worm Rot on me for like five turns straight as I simply clubbed it to death.

Well, this was done for most of the uniques/bosses, although yes, might be wise...