Devouring Plague

Devouring Plague is a Shadow-based Life Drain Damage over Time priest spell, which heals the caster for 15% of the damage done.

Talent improvements
Shadow:
 * Vampiric Embrace (passive): Fills you with the embrace of Shadow energy, causing you to be healed for 6% and other party members to be healed for 3% of any single-target Shadow spell damage you deal. When improved with this talent, Devouring Plague will heal the priest for 21% of the damage dealt.
 * Improved Devouring Plague: Your Devouring Plague instantly deals damage equal to 15/30% of its total periodic effect.
 * Shadowform increases the damage done by 15%, and the priest's haste by 5%, increasing the speed and potentially number of ticks granted by Devouring Plague.

Discipline:
 * Twin Disciplines increases the healing and damage done by 2/4/6%.
 * Mental Agility reduces the mana cost by 4/7/10%.

Tips and Tactics

 * Shadow priests can deal an immense amount of damage with just Shadow Word: Pain and Devouring Plague.
 * Unlike Shadow Word: Pain, Devouring Plague can only affect one target at a time.
 * Devouring Plague cannot be dispelled by a Warlock's felhunter, which makes it an interesting option in duels.