Haunt - Grasping Spirit
Spirit Barrage - Manitou
Spirit Walk - Honored Guest
Soul Harvest - Siphon
Horrify - Frightening Aspect
Mass Confusion - Paranoia
Rush of Essence
A pure Spirit WD requires TONS of mana regen. With Spirit Walk on 13 second cooldown you can get 30% mana back in just 2 seconds. When all the spells with CD are active the natural mana regen increases by 300%. Every skill regens 30% of the mana cost. So mana shouldn't be a problem.
Haunt provides a snare.
Spirit Walk is a nice getaway skill.
Soul Harvest can heal for almost 11,000 if there are enough targets. Soul Harvest also increases INT by as much as 650 points which increases all resists for WD.
Horrify gives a 100% armor bonus for 40% of the time.
Mass Confusion confuses enemies - duh.
Spirit Vessel has the auto WD respawn, hopefully followed by Spirit Walk to escape from the danger and resest all the skills.
Haunt is a time bomb.
Spirit Barrage - Not sure about the best rune for this skill. Might change it to lifegain or mana regen if the current skills and runes don't suffice. For DPS I'm not sure which rune is best with this build. Do the extra spirits from Well of Souls only attack multiple targets, or will all of them converge on a single target?
Mass Confusion has interesting possibilities as a simultaneous defensive and offensive skill. Paranoia provides an overall DPS bonus of 20% for 20% of the time. Might change it to Mass Hysteria if the extra DPS seems too low and the I need an additional CC option.