HotA IK Barbarian Skills and Runes

Active Skills
Furious Charge Merciless Assault Hammer of the Ancients Smash 1 Battle Rage Bloodshed 2 Threatening Shout Falter 3 Wrath of the Berserker Insanity 4 Call of the Ancients Together as One
Passive Skills
Berserker Rage Rampage Ruthless Nerves of Steel

Activate Call of the Ancients and Wrath of the Berserker as soon as you start a run, and keep both skills up throughout the rift — a task made infinitely easier with the Immortal King set bonus. Remember that Wrath of the Berserker needs to be cast on cooldown, but only resummon Call of the Ancients when one or more of them die off. Once you find an area suitably dense with enemies, begin your Hammer of the Ancients assault, only stopping to refresh your Band of Might bonus with a Furious Charge. Furious Charge will also be used for mobility, finding new fights or dodging dangerous situations in this otherwise static, methodical playstyle. On the buff side, apply Battle Rage at regular intervals, and try your best to pop Threatening Shout right before you begin your burst during the Fire rotation of Convention of Elements.

Your primary damage dealer is the namesake of the build, Hammer of the Ancients. Considered as a beginner build staple for a long time, it becomes an endgame viable spender through the Bracers of the First Men (see this build's gear page for more information), skyrocketing its damage and increasing its attack speed by 50%. The rune of choice is Smash, as its higher base damage trumps the utility bonuses of the other options.

While it is certainly not the focus of the build, both spec and gear-wise, Furious Charge brings great utility to the deliberate pace of this build. Akin to a Swiss knife, it brings mobility, Fury generation, and a proc for Band of Might. The rune of choice is Merciless Assault; the dissonance of elemental damage with the rest of the build is not a concern, as the self-sufficient cooldown reset is what you are truly after — hitting 5 or more enemies will instantly reset Furious Charge.

The Immortal King set bonuses allow for the permanent uptime of two hallmark, long-cooldown Barbarian skills: Call of the Ancients and Wrath of the Berserker. Note that their permanent uptime (and consequently, timely re-application) is important to keep up the bonuses of Remorseless.

• The 2-piece bonus removes the duration of Call of the Ancients, allowing you to benefit from the trio of warriors until they are killed. Sturdy as they are, powerful affixes and bad fights can result in one or more of them falling in battle — so keep an eye on their counter and resummon immediately. The 4-piece IK bonus assists you with the cooldown reset for a reason — the chosen rune Together as One is the foundation of your toughness, while the Ancients' Fury rune (acquired from the worn Fury of the Ancients) is the basis of Fury management.
• No superlatives should be spared when talking about Wrath of the Berserker, especially when paired with the damage amplifier of the Insanity rune. For the sake of brevity, this is the single most powerful self-buff of Barbarians, providing you with significant amounts of Dodge, Crit Chance, Attack and Movement Speed. Easily reaching permanency through the Immortal King 4-piece bonus, this skill is a fixture to the build. As soon as you obtain the powers of the Mortick's Brace, which adds all the runes of Wrath of the Berserker to the build, this skill slot selection becomes a no-brainer.

On the topic of buffs, two additional skills round out the category — the offensive Battle Rage and the debuff Threatening Shout.

• Battle Rage is a staple of the class, bumping up both damage and Crit Chance. While its 2-minute duration can catch you off guard, never allow Battle Rage to drop — it is a solid source of damage, especially with the AoE-oriented Bloodshed rune. As this build is limited in sources of healing, you can consider spamming Battle Rage out of combat to heal up through Life per Fury Spent on gear.
• Flipping the traditionally defensive Threatening Shout skill into a debuff, the Falter rune makes affected enemies more susceptible to damage. Timing the use of this debuff directly prior to Fire CoE rotation will ensure you have the extra damage for the entire duration of your 4-second burst window. Note that there is a viable alteration in this skill slot, which makes the build slightly harder to play, but increases its GR pushing potential; slotting Ancient Spear Rage Flip instead, and using it to create big pulls of enemies for the convenience of your AoE destruction.

Able to burst and hop between targets better than many Barbarian builds, the HotA Barb is a natural adopter of the Rampage passive. Learning to maximize this passive is important, as it is a true multiplier with the potential to net you 25% additional Strength, increasing DPS and Toughness substantially. Staying at or near the cap can only be achieved if you stay vigilant and on the move, aiming to get in bigger fights, where killing minor enemies will feed your stacks. If you find yourself unable to sustain this passive at the highest ends of GR progression, you can viably alternate this slot to the additive damage increase of Brawler.

While the build is resource intensive, you quickly regain what was lost — your cubed weapon will refund Fury, your ancients will give Fury per hit, and both Threatening Shout and Furious Charge are generators. The result is a fairly stable resource pool, allowing you to take full advantage of the additive damage increase of Berserker Rage.

Hardly lacking single target damage, the HotA Barb still incorporates Ruthless — a testament to the quality of the passive. Once you hammer your target below 30% health, your damage spikes with a 40% multiplier,allowing you to tear down your target even quicker.

Your final passive slot is flexible, with a number of viable and useful options. As the build is prone to getting spiked in damage, is not as fluid as the Whirlwind Barb, and suffers for sources of healing, Relentless can be a nice fit — allowing you to stand your ground and regain health. A second life is never a bad option, making Nerves of Steel an attractive pickup. If you feel the need for additional damage, take whichever passive you initially dropped between Brawler and Rampage; if you find the latter impossible to keep up reliably, alternate to Weapons Master.