LoD Rapid Fire Demon Hunter Skills and Runes

Active Skills
Rapid Fire Bombardment Preparation Focused Mind 1 Companion Wolf Companion 2 Shadow Power Gloom 3 Fan of Knives Bladed Armor 4 Vengeance Side Cannons
Passive Skills
Cull the Weak Grenadier Ambush Numbing Traps

The LoN Rapid Fire build has a fairly simple rotation — it begins runs by activating Vengeance, which has permanent uptime with a combination of Dawn and CDR on gear, and reapplies it on cooldown. The same goes for Fan of Knives, which is added to the build simply for the defensive value of Bladed Armor. Try to be slightly more conservative with Shadow Power, as it chews through Discipline (though you can still apply it on cooldown in any significant fight, since you can pop the Discipline-over-time restoration effect of Preparation Focused Mind. Once you have a dense pack of monsters engaged, you should trigger your Wolf Companion for a decent temporary boost of damage. Try to sync it with other sources of increased damage, like the Fire cycle of Convention of Elements and/or when you are standing in the circle of an Oculus Ring proc. Needless to say, all of your damage will come from channeling Rapid Fire — simply plant yourself in place and channel away.

Rapid Fire is the primary damage dealing skill of the build — a channeled, low-to-mid range cone AoE with a rather expensive Hatred cost, which you will eliminate almost with a combination of Sin Seekers (for the channel cost) and Cindercoat (for the activation cost). The rune of choice is Rapid Fire Bombardment, as it not only has elemental synergy with your Fire-based item options, but also Grenade-based synergy with Hellcat Waistguard.

A trio of strong defensive skills will bear the brunt of your protection. The staple steroid skill of Demon Hunters, Vengeance, is included not only for its baseline 40% multiplicative damage increase, but also the 50% damage reduction of the Dark Heart rune. Note that this rune will come for free from a worn Visage of Gunes, so you are free to take defensive utility even further with the health sustain rune Side Cannons. While Vengeance requires 37% cooldown reduction for permanent uptime (also noted in the gearing section below), you will do well to bump up your CDR slightly higher (three 8% CDR slots for nearly 40% CDR is quite enough), which allows you practically permanent uptime of the 40% armor buff of Fan of Knives Bladed Armor as well. Fan of Knives will also serve as a proc for Numbing Traps, Cull the Weak and Bane of the Trapped in a single, extremely convenient shot. Lastly, Shadow Power will be taken with the Gloom rune for a short emergency bump to your damage reduction, but with careful management of Preparation, you will be able to pop it quite liberally. Remember to cast it at least once every 8 seconds to trigger the damage reduction of your cubed Elusive Ring.

Speaking of Preparation, this signature utility skill will provide all the necessary Discipline to be reasonably trigger-happy with Shadow Power with its strongest restoration rune, Focused Mind. An alternative for this slot is the repositioning powerhouse Smoke Screen Vanishing Powder, which presents a powerful alteration for high end GR pushing. If you decide to alternate to a glass cannon Smoke Screen setup, you should also drop Fan of Knives for the damage bonuses of Caltrops Bait the Trap.

With multiple utilities to pick from, the LoN Rapid Fire Demon Hunter is generally recommended to take the DPS buff role for the Companion skill through the Wolf Companion rune, boosting you with a temporary multiplicative damage increase. While the Wolf Companion buff sports a generous 10-second uptime, the skill has a reasonably long cooldown and is only up 50% of the time — so try to pop the Companion active in sync with other buffs like the Fire Convention of Elements cycle, Oculus Ring procs, or taking a Pylon buff.

This concludes the overview of the Active Skills, now let us look through the Passives.

Ambush complements the burst-oriented nature of the build, frontloading your damage potential against newly encountered enemies. The multiplicative nature of the passive sweetens the 40% damage increase offered, and leads to the unrivaled performance of LoN FoK builds against trash packs.

Cull the Weak is a Demon Hunter mainstay, bringing a multiplicative damage increase against Slowed or Chilled enemies. You will easily reap the benefits of this passive with the help of the Bane of the Trapped and Bladed Armor slows. Those slows, of course, come from the inclusion of Numbing Traps, which also bring valuable, near-permanent damage reduction debuff on affected enemies.

Grenadier is understandably a signature passive for grenade-based builds, bringing a 10% multiplicative damage increase to the related skills and increasing their explosion radius by 20% — a bonus that is hard to quantify, but undeniable in effectiveness. For softcore players, it also brings an amusing on-death detonation that fully benefits from the grenade-related bonuses in the build.