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  "description": "HP-scaling relics, the best Light Cones, and the teams that turn his Zone into constant damage.",
  "path": "/mortenax-blade-build-guide-for-honkai-star-rail-4-3/",
  "publishedAt": "2026-06-01T12:49:36.000Z",
  "site": "https://allthings.how",
  "textContent": "Mortenax Blade is a 5-star Fire character on the Nihility path in _Honkai: Star Rail_ , and he plays nothing like a standard debuffer. He spends his own HP to deal damage, drops a Zone that weakens enemies, and flips into an aggressive damage state once his Ultimate goes off. The catch is that all of his stats scale with Max HP, so the build looks very different from a typical attack-based DPS.\n\n🔥\n\nQuick answer: Run his signature Light Cone Reforged in Hellfire, pair the Smith's Fire Beast Mask 4-piece relic set with the Bone Collection's Serene Demesne planar set, and prioritize CRIT Rate, CRIT DMG, and HP% on your gear. Level his Ultimate first.\n\n* * *\n\n## How Mortenax Blade works\n\nBefore his Ultimate, Mortenax Blade behaves like a support. He inflicts \"Balefire Bind,\" which cuts enemy DEF by 30% and raises the damage they take by 50% for two turns. He then spends 30% of his Max HP to deploy a Zone and enters the \"Infinite Fury\" state.\n\nInside Infinite Fury, his CRIT Rate goes up by 20% and CRIT DMG by 60%, his Skill unlocks, and he gains the new Ultimate \"Tenax Per Ignem,\" which deals Fire damage equal to 300% of his Max HP to all enemies. His Skill, \"A Rain of Blades Seals Fate,\" costs 15% of Max HP and hits the field for AoE Fire damage that also scales off his Max HP.\n\nThe loop that ties it together is his Talent, \"All Karma Comes Due.\" While the Zone is active, every ally attack applies Balefire Bind and grants him 1 Charge. At 9 Charge he regenerates 25 Energy and casts his Skill one extra time for free, counted as a Follow-Up attack. That is why fast-acting allies and Follow-Up attackers feed him so well.\n\nOne survivability note worth knowing. If a killing blow lands while he is in Infinite Fury, he is not knocked down. Instead, the Zone disperses, he leaves the state, and he heals 50% of his Max HP. He also can only use his Skill while inside Infinite Fury.\n\n* * *\n\n## Best relics for Mortenax Blade\n\nThe best-in-slot cavern set is **Smith's Fire Beast Mask**. It gives him the two stats he wants most, HP% and CRIT DMG, and its 4-piece bonus pushes a 15% team-wide damage buff through the DEF reduction he constantly applies. That doubles as a personal CRIT DMG boost against DEF-reduced targets.\n\nIf you don't have it built, **Pioneer Diver of Dead Waters** is the next pick. His personal damage barely drops, but the team loses the supportive buff, which makes it weaker overall. **Longevous Disciple** is also a stable option since he constantly consumes his own HP, keeping the CRIT Rate stacks active without setup.\n\nRelic set| 2-piece| 4-piece\n---|---|---\nSmith's Fire Beast Mask| Max HP +12%| +28% CRIT DMG against DEF-reduced enemies; applying DEF reduction grants allies \"Comburent\" for +15% damage\nPioneer Diver of Dead Waters| +12% damage to debuffed enemies| +4% CRIT Rate; +8%/12% CRIT DMG vs enemies with 2/3 debuffs, doubled for 1 turn after applying a debuff\nLongevous Disciple| Max HP +12%| +8% CRIT Rate (up to 2 stacks) when hit or when HP is consumed\n\nFor planar ornaments, **Bone Collection's Serene Demesne** is the top choice. It adds 12% Max HP and grants 28% CRIT DMG once his Max HP reaches 5,000 or higher, which is easy for an HP-scaler. **Duran, Dynasty of Running Wolves** works well in Follow-Up teams, and **Inert Salsotto** is a clean CRIT-focused backup.\n\n* * *\n\n## Best Light Cones for Mortenax Blade\n\nHis signature Light Cone, **Reforged in Hellfire** , is the clear best option. It increases Max HP by 30% and, once per wave, restores a fixed 20 Energy at the start of his turn. That Energy is the key piece. Without it, he struggles to land a turn-zero Ultimate and his Zone uptime drops sharply. The cone also applies \"Purgatory\" after a Skill attack, raising CRIT DMG taken by the target.\n\nIf you don't have the signature, **Lies Dance on the Breeze** is a strong 5-star alternative that boosts SPD and stacks DEF reduction. For a budget pick, **Resolution Shines As Pearls of Sweat** covers DEF shred at 4-star rarity.\n\nLight Cone| Rarity| Why it fits\n---|---|---\nReforged in Hellfire| 5★| +30% Max HP and fixed 20 Energy per wave for reliable Ultimate uptime\nLies Dance on the Breeze| 5★| +18% SPD plus layered DEF reduction on enemies\nResolution Shines As Pearls of Sweat| 4★| Cheap DEF shred via the \"Ensnare\" debuff\n\n* * *\n\n## Stat priority and trace order\n\nBecause his damage is built on Max HP and CRIT, you want crit substats and HP layered on top. Speed matters for keeping Charge and Zone rotations smooth.\n\nSlot| Main stat\n---|---\nBody| CRIT Rate or CRIT DMG\nFeet| Speed, then HP%\nPlanar Sphere| HP%\nLink Rope| HP%, then Energy Regen Rate\nSubstats| CRIT Rate / CRIT DMG, then HP%, then SPD\n\nFor traces, upgrade his **Ultimate first**. It triggers Infinite Fury, plants the Zone, applies Balefire Bind, and unlocks the rest of his kit. His **Skill** comes next as his main damage source, followed by his **Talent** for the support side. His **Basic Attack** is last and offers the least value.\n\n* * *\n\n## Best teams for Mortenax Blade\n\nMortenax Blade slots into almost any team that needs damage amplification, but he shines hardest next to DPS units that lean on their Ultimate or attack often. Every ally hit during his Zone feeds his Charge, so high action frequency directly translates into more of his free Skill casts.\n\n**Acheron** is one of his strongest partners. His steady Balefire Bind application accelerates her Ultimate generation, and he fills her required Nihility slot. With a second Nihility unit present, his \"Heart, Refined ad Infinitum\" trace grants the team increased Ultimate damage, which stacks beautifully with her kit.\n\n**Ashveil** and **Feixiao** are excellent Follow-Up and high-action DPS pairings, since their frequent attacks rush his Charge to 9 and trigger extra Skill damage. **Tribbie** is a standout support because she also scales with HP, raises the team's Max HP, and triggers Follow-Up attacks, lifting both herself and Blade.\n\nTeam| Core idea\n---|---\nMortenax Blade · Acheron · Cipher · Huohuo| Stack debuffs and Nihility synergy to fire Acheron's Ultimate repeatedly\nMortenax Blade · Ashveil · Tribbie · Hyacine| HP-scaling Follow-Up core with Hyacine raising everyone's Max HP\nMortenax Blade · Feixiao · Tribbie · Hyacine| High action frequency to spam his Charge-fueled extra Skills\nMortenax Blade · Acheron · Jiaoqiu · Hyacine| Heavy debuff stacking around Acheron's burst windows\n\nSustain is flexible. Hyacine is the ideal healer because she boosts his Max HP, while Huohuo or Gallagher work when you want ATK buffs and Energy support instead. His Technique and traces also make him tanky enough that you can occasionally run him without a dedicated healer, leaning on his taunt and the 50% heal he gets when a killing blow lands in Infinite Fury.\n\n💡\n\nTip: Since he scales with Max HP and not ATK%, pairing him with HP-buffing supports like Tribbie and Hyacine raises both his damage and his survivability at the same time.\n\nBuild him around HP, CRIT, and Energy, keep his Zone up, and let the team's attacks do the rest. Once the Charge loop is running, his free Follow-Up Skills and the constant Balefire Bind turn him into both a debuffer and a steady AoE damage dealer in the same slot.",
  "title": "Mortenax Blade Build Guide for Honkai: Star Rail (4.3)",
  "updatedAt": "2026-06-01T12:49:38.288Z"
}