One's minions can be consumed for more than just a quick heal. The negative energy of undead under your control can be transformed into a powerful attack to destroy your foes. On the completion of this dark ritual any adjacent undead will be so converted.
It is rumoured that this spell is the first step in transforming into a lich.
- Tome of Necromancy
The effect of Dark Ritual depends on what direction the undead pet is from you when you cast it
North: Deals 1d6 damage and inflicts harsh poison for 5d3 turns (dealing 4d3 damage every 2 turns)
West: Deals 6d3 cold damage and inflicts slow for 3+3d3 turns
East: Deals 6d6 acid damage
South: Deals 1d60 shock damage