Jackal, Sailor's Guide, Assassin's Blade, Eel, Hawk, Lotus
Manticore, Harvestman's Scythe, Bard's Harp, Ulzaad, Herald of Korvaak, Solemn Watcher, Typhos, the Jailor of Souls
Azrakaa, the Eternal Sands, Ishtak, the Spring Maiden, Korvaak, the Eldritch Sun, Obelisk of Menhir, Light of Empyrion
WEAPON 1: Lawbringer (runeword craft)
WEAPON 2: Breath of the Dying one-handed mace (runeword craft)
HELM: Harlequin Crest (drop; look for >900 life and 12% phys resist)
CHEST: Chains of Honor (runeword craft; look for 12% phys resist)
SHOULDERS: Mythical Shoulderguards of Justice (drop; can substitute Mythical Warborn Pauldrons, Shattered Realm Mantle, or a rare; if you're short on ele>phys facets, consider Targo's Shoulderguards)
PANTS: Mythical Chausses of Barbaros (drop; can substitute Mythical Rimestone Legguards or a rare)
GLOVES: Mythical Colossal Grasp (drop; can substitute a rare)
BOOTS: Gore Riders (drop; look for high values in "reduction to enemy's health" and "total damage modified by")
BELT: Mythical Chains of Anguish (anvil craft from a randomly-dropped recipe; substitute Arachnid Mesh if you don't have the recipe or can't stand the occasional debuff, but Chains is BIS overall)
AMULET: Mara's Kaleidoscope (drop)
RINGS: 2x Bul-Kathos' Wedding Ring (drop)
MEDAL: Annihilus (drop from Uber Trist; bonus to Maul would be BIS, followed by Hurricane or WW, but any Anni is fine)
RELIC: Titan's Trinket w/ Concentration aura (drop from Brutalus)
Components / Augments
Weapons/Chest/Head: 3x Gul (for AR), 1x Cham (for status resistances).
Amulet/Rings/Medal: 4x elemental>physical facets. If you don't have four, substitute cold>phys, lit>phys, or fire>phys (in that order of preference) until you do.
Shoulders: Living Armor.
Boots: Mark of the Traveler. You could use Mark of Mogdrogen for more life, but I prefer the slow resistance.
Pants/Gloves/Belt: Mix and match Ugdenbog Leather (for overcapping poison resist), Enchanted Earth (for life), and Bladed Plating (for AR). I use 2x Leather and 1x Earth.
All Armor: Solael's Bloodbinding (Shattered Conclave).
Weapons: 2x Coven's Terror (Act 5).
Jewelry: 3x Survivor's Ingenuity (Act 2).
Mercenary: Act 4 Offensive for AR and crit damage.
Barb class mastery - MAX
Whirlwind - MAX
Berserker Rage - MAX
Mace Mastery - MAX
Increased Speed - MAX
Shout - MAX
Battle Orders - at least 1 point, plus all spare points you don't invest elsewhere
Battle Command - enough points to bring it to level 31 after its own buff is applied
Natural Resistance - about 5 points (however many it takes to get your elemental and poison resists to 60% overcap)
Increased Stamina - 1 point
Iron Skin - 1 point
War Cry - 1 point (for breaking pots)
Double Swing - 1 point (enables dual wield)
Earthquake - 1 point (for extra crushing blows and triggering devotion powers)
Druid class mastery - MAX (but last 10 points can wait until level 95+)
Hurricane - MAX
Maul - MAX
Oak Sage - MAX
Heart of the Wolverine - MAX
Fissure - 1 point (for extra crushing blows and triggering devotion powers)
Spirit of Barbs - 1 point
Werebear - 1 point (prereq for Maul)
NOTE: Skills in the screenshots are from a level 97 build with all campaign and SR quests completed.
75% Strength, 25% Dexterity, 0 Intelligence. Adjust these ratios as desired for more AR (Dex) or life+Def (Str).
The Whirlwind Reaper is a spinning murder-top with fast movement speed, huge AoE, and top-tier defenses. It is particularly good for fast SR 90 runs, as well as cows and Hidden Ubers. Uber Tristam is more challenging, but it still clears all three bosses deathless in 4-5 minutes. It stacks elemental damage with skills like Hurricane and devotions like Light of Empyrion, then converts that damage to physical to take advantage of Lawbringer's enormous physical resist reduction. With Maul as a single-target attack, it has >6000 AR and +130% crit damage. Defensively, it has an incredible 35k-40k life, huge life/mana leech, high resistance to all status ailments, ~5000 Defense, and over 50% physical resist to compensate for Berserker Rage's armor reduction. It is quite difficult to kill this build once it's fully geared.
Milestones: all Hidden Ubers deathless (including bugged Infernus and Deathclaw), Uber Tristram deathless, ~2 min average SR 90
Keep Hurricane active and spin2win through packs. Hurricane and Whirlwind complement each other perfectly: Hurricane compensates for Whirlwind's small AoE, while Whirlwind compensates for Hurricane's slow hit rate. You may have mana issues using Whirlwind against weak enemies like Bloody Fields mobs because they die before BotD can hit them to leech mana; just use an occasional mana potion to top up. Against cows, packs of SR rares, or SR bosses, drop Fissure and/or Earthquake under the center of the pack for their devotion powers and crushing blows. For optional extra crit chance, keep at least one Maul charge active for its AR bonus.
Against bosses, spam Maul and make sure to keep both Fissure and Earthquake active. Those spells are a crucial source of crushing blow hits and they trigger valuable buffs (Ulzaad) and debuffs (Assassin's Blade). You can safely facetank most boss mechanics, but watch out for any debuff that reduces your total damage or gives you a fumble chance. Both of these effects interfere with your life leech, and since leech is an important part of the build's defense, this can be dangerous. If you start taking serious damage, chug a health potion and run out of the fight until the debuffs wear off. Notable bosses which use these mechanics are Deathclaw (probably the most dangerous boss for this build even after he gets patched), Lilith, Uber Mephisto, and Uber Baal.
As a bonus, this build makes your mercenary very tanky. Most of your defensive buffs are auras, giving your merc far more HP and defense than the average templar. She will typically survive a Hidden Uber fight or an SR 90 run. Uber Tristram will still crush her quickly, since you aren't buffing her resists, but she can handle the rest of RoT quite well.
Complete all listed T1 and T2 devotions, and also keep two points in Crossroads for red (Chaos) and green (Eldritch).
T3 devotions: complete Korvaak, get everything but the power in Empyrion and Azrakaa, three points in Ishtak, and two points in Obelisk (I prefer the 5% defense node but the flat Def plus armor node is also a good choice).
Manticore > Maul
Assassin's Blade > Fissure
Ulzaad > Earthquake
Korvaak > Whirlwind
Bard's Harp > Shout (or any other toggled buff except Werebear)
Stack physical resistance on your gear to compensate for the armor debuff from Berserker Rage. As mentioned above, my build has over 50% physical resist.
It is not worth swapping Gore Riders for move speed boots; you will be close to the move speed cap of 250% in any case. I have 248% move speed with Gores and the Battlecry buff from Chausses of Barbaros.
The most important status resist to cap is stun. Cham solves that problem by itself, but if you don't have one, you can still cap your stun resist. Swap your pants for Mythical Rimestone Legguards, remove three points from the Ishtak devotion, and add those point to Obelisk. You may also need to spend a few skill points on Increased Stamina.
UBER TRISTRAM TIPS
Use resist potions (Flamedrinker Ointment, etc.) to increase your elemental and poison resists to 90% overcapped. If you plan to run Uber Trist regularly on this build, swap some of your augments for lightning resist to get lightning resist 120% overcapped; this is not strictly necessary given this build's huge life total, but it helps avoid damage spikes from Uber Baal.
If you are using Chains of Anguish - which I recommend in most circumstances - consider swapping it for Arachnid Mesh for Uber Trist. This build almost never dies, but I'm pretty sure that those few deaths were caused by badly-timed Anguish procs reducing my resists.
When you see the red-sword debuff icon, run out of the fight until it wears off. This debuff practically eliminates your damage; you don't gain anything by staying in combat, and you're more vulnerable because it's reducing your life leech.
Finally, make sure to fight the bosses one at a time! This build *cannot* fight two Uber Trist bosses simultaneously; if you want that, roll a Hydra Sorc.
Leveling Guide (If Applicable)
I leveled with a different build in mind, but respecced to this when I found that I didn't like my original playstyle. This leveling advice is therefore SPECULATIVE, since I haven't actually leveled this way myself. Furthermore, this build relies on Breath of the Dying and four elemental>physical facets, so I doubt it would work well for someone new to RoT.
In general, you should be able to power through Normal and Nightmare as a fire caster. Start with Firestorm, then trade up to the next tier of fire spells as you get enough skill points. At level 15-16, respec to Hurricane and you will be set for clearing for quite some time. Combine Hurricane with Fissure, Volcano, or Armageddon (whichever you prefer). Also stat up Werebear, Oak Spirit, and Heart of the Wolverine for their buffs. Around level 40, you should be good to start taking points in Barbarian. Stack points in Increased Speed for its cooldown reduction, which will benefit your cooldown-limited fire spells. Get one point in Battle Command, and don't neglect Shout, Battle Orders, or the other Barbarian passives. You should be in good shape to respec to the actual Whirlwind Reaper build around level 75; if you have access to your endgame GD items (which require level 94, or 89 with Gore Riders), use Ist runes to lower their level requirements so you can use them immediately.
For leveling devotions, take advantage of the free respecs to grab elemental damage devotions. Get Rhowan's Crown ASAP (my preferred path is Scholar's Candle + Quill + Xroads Purple = Rhowan's Crown) and bind its power to your fire spell. After that, get other purple/green devotions to work toward Blind Sage and Attak Seru. Since this is a tri-element leveling build, try to get elemental damage instead of just fire, lightning, or cold damage.