Just started running this build, very effective with my set up of decent EHP and a 6% life steal skorn. MP 8 & 9 are cake now and mp10 is slightly slower but still very manageable.
1) Fire Bats: Cloud of Bats
2) Soul Harvest: Vengeful Spirit
3) Spirit Walk: Honored Guest
1) Grave Injustice- 2% of life and mana on kill and reduced cooldowns on kill make this an irreplaceable passive.
2a) Spiritual Attunement- Increased mana regen help with channeling fire bats indefinitely.
2b) Blood Ritual- As many WDs with higher hp have pointed out, this skill can be just as effective as the increased mana regen gained from spiritual attunement.
Remaining skill options that I like:
1) Zombie Bears- great for hitting ranged elites that you are having difficulty standing next to with fire bats.
2) Hex: Jinx- great for CC on 1v1 battles with elites.
3) Mass Confusion: Paranoia- Great for CC and increased dmg against mobs and elites.
4) 0 Dogs- I haven't tested this but I imagine that it would be very viable (post how it goes if you try it out).
1) Spirit Vessel- Reduced cooldown on spirit walk and soul harvest help out and the fatal damage save can really help when you are getting the hang of the build or if you underestimate a mob that you just spirit walked in the middle of.
2) Jungle Fortitude- 15% less dmg taken, nuff said.
My firebats are hittin around 1.3-2m crits and I am able to channel it indefinitely using spiritual attunement.
Having the reduced cooldowns on soul harvest and spirit walk from grave injustice allows you to spirit walk into the middle of huge mobs and just spam firebats while alternating SH and SW as they cooldown.
The rest of the skills can be swapped out to fit your individual play style.
Try it out for yourselves and let me know what you think!