Which magic schools should I choose for the late game? Or should I go for a specific artifact?

I was just joking! I didn't think it would be taken seriously, but I agree, the vampire and speed-boosting gimmick is brutal... And against creatures like Orcs and Demons, you definitely need a lot of Darkness, no question... I'd also take Summoning magic! It's rare to find someone with a sharp mind, which is a shame, but otherwise, put mines in front of the Orcs (to relieve their rage) and charge!