I don't understand why everyone loves Lethos so much. What's the point of dark magic for him if berserk, mind control, or vampirism will never drop in the guild? High spell power, low knowledge, and darkness means that low-level spells won't have any advantage over other dark spellcasters. His specialization is also questionable, as there's too much randomness. And because of dark magic, you can't learn summoning or chaos spells, which can ruin your build. I think there's no doubt that warlocks have a significant advantage over many in these two schools, so why not use that advantage?