Ah the "Dark Magic." This can be a much more usful skill than you would think.You'll need to got Umbra and buy yourself the Necromancy Book off the mages/necromancers in the magic shop.From there you're on your way to the dark side of magic.
Skill Training
Skill level What to cast
0-30 Buy/Curse Weapon
30-54 Pain Spike or Wraith Form
54-71 Horrific Beast
71-81 Wither
81-110 Lich Form
110-120 Vampiric Embrace