Push Critical Strike Chance first
For this setup, Critical Strike Chance is the stat you don't want to treat as optional. Heir of Perdition is a huge part of the damage package, but it needs the right Masterworking attention. If a Masterwork lands on Movement Speed, that's not awful. It feels nice in dungeons. Still, it's not the main prize. Lucky Hit Chance is even less exciting here, since the build isn't leaning on it to function. The real win is landing upgrades on Critical Strike Chance, then building the rest of the gear around that same idea.

Do not ignore Gohr's Devastating Grips
Gohr's Devastating Grips are one of those items people equip and then forget to finish. That's a mistake. The gloves should be Masterworked, and the best hits should go into Critical Strike Chance whenever possible. Tempering matters too. Overpower damage on the gloves gives the build a much better punch when the big burst window lines up. Also, check the unique power roll. A weak roll on Gohr's can quietly hold the whole build back. If it's near the bottom, rerolling or replacing the pair is usually worth the pain.

Clean up armour and movement slots
The chest, pants, and boots are where the build starts to feel smooth instead of clunky. On a chest such as Archon Armor of Booming Voice, Fury Generation is a big deal. Without enough resource flow, Whirlwind stops feeling immortal and starts feeling awkward. Single resistances can work for a while, but All Elemental Resistances is the safer pick when you're pushing harder content. Pants and boots should also be checked for item power and Greater Affixes. If you're still wearing an 850 piece with no real standout stat, it's probably time to move on. On boots, Greater Affix Movement Speed is one of those upgrades you feel right away.

Weapons and jewellery decide the ceiling
The weapon setup needs the same level of inspection. A strong two-handed mace with Limitless Rage, Ramaladni's Magnum Opus, and properly rolled supporting weapons can push Whirlwind damage much higher than a random mix of high item power sticks. Don't just look at the damage number. Check for the right affixes, especially Critical Strike Chance where it can appear, and make sure the aspects support constant Fury spending. Ring of Starless Skies helps a lot with resource control, but a version leaning into crit value will serve the build better than one loaded with Lucky Hit.

Finish Selig properly
Melted Heart of Selig is the piece that makes the build earn the word immortal. It turns resource into a defensive layer, and when Fury generation is strong, you can face-tank far more than you probably should. But it still needs to be finished. Add sockets with prisms, place the right gems or seasonal tools, and don't leave easy power sitting unused. If you're planning upgrades, repairs, or market moves around buy D4 Gold, make sure Selig, Gohr's, and your crit rolls are handled before chasing tiny side improvements.