Arachyr Firebats Witch Doctor Skills and Runes

Active Skills
Firebats Cloud of Bats Haunt Poisoned Spirit 1 Hex Jinx 2 Spirit Walk Honored Guest 3 Soul Harvest Languish 4 Locust Swarm Cloud of Insects
Passive Skills
Creeping Death Confidence Ritual Spirit Vessel Grave Injustice

In an Arachyr build Hex needs to be cast on cooldown, as it is a source of damage reduction from the Arachyr 4-piece bonus, as well as a damage buff through the rune Jinx. With the Helltooth set, the same purpose will be fulfilled by Wall of Death Communing with Spirits — reapplying the Damage Reduction from the Helltooth 4-piece set bonus as soon as the skill comes off cooldown. Prior to channeling major damage, you will need to apply Locust Swarm and Haunt, in order to attain the immense damage benefits from Ring of Emptiness. You will also need to weave in a cast of Soul Harvest, in order to attain the massive defensive and offensive bonuses (but unlike a Jade setup, it does not need to follow up your DoTs — simply try to maximize the number of affected enemies). With that out of the way, you can begin the Firebats onslaught, stopping only to reposition with Spirit Walk.

When using the Arachyr set, Hex will be used on cooldown for its interaction with the Arachyr 4-piece bonus (damage reduction and a free Toad of Hugeness rune), as well as a minor damage buff from the slotted Jinx rune.

The build dedicates two skill slots to trigger the crucial damage multiplication bonuses of Ring of Emptiness. One of them is Locust Swarm; during Greater Rift progression, you will ideally be wearing the Vile Hive mojo and getting the Pestilence rune for free, allowing you to slot the protective Cloud of Insects instead. The other Ring of Emptiness trigger skill — Haunt — is best taken with the additive damage increase of the Poisoned Spirit rune, but can also be used with the Mana restoring Draining Spirit rune if you struggle with resource management.

Firebats is among the creature skills buffed by the Arachyr set 6-piece bonus, and complemented by synergistic items like Coils of the First Spider, Bakuli Jungle Wraps and Staff of Chiroptera it becomes a Greater Rift pushing-worthy damage dealer. You will be taking the hardest hitting of the runes, the Fire-based Cloud of Bats.

Spirit Walk is another Witch Doctor staple, and its moderate cooldown is compensated by its versatility: it renders you invulnerable, removes enemy collision and increases your movement speed by 50%. The recommended rune is Honored Guest, in order to add a source of emergency Mana regeneration to the build. An alternative for the slot is the rune Severance, whose 100% additional movement speed will allow you to reposition more easily; if you opt for this speedier choice, remember to change your Haunt rune to Draining Spirit.

Finally, you will be taking the Witch Doctor staple Soul Harvest in all variations of the build, but for different reasons. In Greater Rifts, where this build wields a Sacred Harvester, you get an immense 30% Intelligence buff from a reasonable 10 enemy Harvest, as well as cut incoming damage in half and double your Armor via the Languish rune and worn Lakumba's Ornament bracers.

This concludes the overview of the active skills, now let us look through the passives.

Conveniently matching the fighting radius of Firebats, the Confidence Ritual passive will reliably increase damage by 25%.

Arachyr Doctors take Creeping Death during Greater Rift progression to extend the benefits of the their two DoTs and, more importantly, keep the valuable Cloud of Insects Damage Reduction and Draining Spirit Mana regeneration going.

Grave Injustice is a universally desired passive for this build, as it acts as a more universal In-geom; reducing your vital defensive and mobility cooldowns without distinguishing between trash and elites.

Spirit Vessel should be carefully considered for the final slot when pushing Greater Rifts as a soloing Witch Doctor, similarly to other cheat death passives for other classes. On top of the second life proc, it heals you to 50% of your maximum health and triggers a Spirit Walk-like effect, allowing you to escape danger.

If you prefer to play this build while using the Helltooth set variation, you will only need to change one skill (and, of course, swap your equipped set to Helltooth). Hex will be replaced by Wall of Death Communing with Spirits, and will pretty much fulfill the same purposes — triggering the set-based damage reduction and boosting the damage of your Mana spender with the Necrosis debuff.