Spiteful Spirit

Elite Hex Spell. For 8...18...20 seconds, whenever target foe attacks or uses a skill, Spiteful Spirit deals 5...29...35 shadow damage to that foe and all adjacent allies of that foe.

Elite Hex Spell. (8...18...20 seconds.) Deals 5...29...35 damage to target and adjacent foes whenever this foe attacks or uses a skill.

Progression
Curses Duration Shadow damage	0 8 5 1 9 7 2 10 9 3 10 11 4 11 13 5 12 15 6 13 17 7 14 19 8 14 21 9 15 23 10 16 25 11 17 27 12 18 29 13 18 31 14 19 33 15 20 35 16 21 37 17 22 39 18 22 41 19 23 43 20 24 45 21 25 47

[edit] Acquisition

Casting this hex on multiple foes that are within the same area of effect will compound the amount of damage caused to all the foes in the group.

Arcane Echo can be used to help facilitate this strategy by duplicating the skill.
Combine with Reckless Haste to have the foe trigger Spiteful Spirit more often.
As a punishment hex, this skill is useful in hard mode as it benefits from the attack and casting speed bonuses foes have.

Heroes will only use this skill on attacking foes.
Capturing this skill from Harvest Soulreign in the mission Against the Charr is difficult because very shortly after he is killed a cinematic will start, and after the cinematic, the corpses have been removed. One solution is to kill Gordam Griefgiver first, and then activate a Signet of Capture when Soulreign is nearly dead; with quick reflexes it is possible to capture Spiteful Spirit before the cinematic.

The three original Prophecies bosses that this skill can be captured from are Nightmares and one also seems to appear in the skill icon.