Mortenax Blade
Who is Mortenax Blade?
Mortenax Blade is a 5★ Fire Nihility HP-scaling sub-DPS and support — the alternate form of Blade (Yingxing), the immortal swordsman of the Stellaron Hunters. Appearing in the dream-realm of the Aeon Aha (Planarcadia), he is described as having "a body like spring wood, a heart like dead ashes, yet the sparks of a craftsman still linger at the fingertips." His kit revolves around his Ultimate-deployed Zone: once active he enters the "Infinite Fury" state, applying a stacking Balefire Bind debuff to all enemies on every ally attack — shredding DEF by 30% and increasing damage received by 50% — while firing follow-up Skill strikes at max Charge. He simultaneously satisfies the Nihility ally requirement for Acheron and pairs powerfully with any high-frequency-action carry.
Kit Summary
Basic ATK — A Broken Blade Still Slays: Deals Fire DMG equal to 50% Max HP to one enemy and inflicts Taunt for 1 turn.
Enhanced Basic ATK — A Tempered Blade Severs Souls: Deals Fire DMG equal to 100% Max HP to one enemy with Taunt; only available in Infinite Fury state.
Skill — A Rain of Blades Seals Fate: Costs 10% Max HP; deals Fire DMG (72% Max HP) to all enemies plus 4 random-target hits at 24% Max HP each. Cannot be used below 1 HP or outside Infinite Fury.
Inflicts Balefire Bind on all enemies (DEF -30%, DMG received +50% for 2 turns). Consumes 20% Max HP to deploy a Zone, entering Infinite Fury state (+20% CRIT Rate, +60% CRIT DMG). Mortenax Blade survives lethal hits while in Infinite Fury by exiting the state and restoring 50% Max HP.
Deals Fire DMG equal to 350% Max HP to all enemies; replaces the normal Ultimate while Infinite Fury is active.
While the Zone is active, every ally attack applies Balefire Bind to the struck enemy and grants Mortenax Blade 1 Charge. At 9 Charges (and HP above 1), consumes all Charges to regenerate 25 Energy and use his Skill once as a free Follow-Up ATK (no HP cost).
Attacks all nearby enemies; upon entering combat Taunts the target for 1 turn and reduces own DMG taken by 90% for 2 turns.
Allows 80 Energy overflow storage; clears overflow after using his Ultimate while regenerating equivalent Energy. Restores Energy to 50% threshold at battle start or when Zone disperses.
While Zone is active, increases enemy targeting rate toward Mortenax Blade, reduces his own DMG taken by 50%, increases Incoming Healing by 50%, inflicts Balefire Bind on attackers, and grants 1 Charge when attacked.
While Zone is active, allied DMG increases by 50%. If another Nihility character is present on the team, ally Ultimate DMG further increases by 75%; otherwise Mortenax Blade's personal DMG increases by 75% instead.
Decreases all enemies' All-Type RES by 20% while Zone is active; delays the Infinite Fury countdown by 15% after each Talent-procced free Skill. (Efficient stopping point for vertical investment.)
Ally Ultimate attacks count as Follow-Up ATKs and gain +75% Follow-Up ATK DMG bonus. (One of the strongest Eidolons — enables ally Ults to generate Charge.)
Ultimate Level +2 (max 15), Talent Level +2 (max 15). (Weak — level-only upgrade.)
A6 Trace grants an additional 50% allied DMG increase. (Decent teamwide amplification.)
Skill Level +2 (max 15), Basic ATK Level +1 (max 10). (Weak — level-only upgrade.)
While Zone is active, gains 1 Charge whenever any target takes DMG or consumes HP (triggers once per target turn). Tenax Per Ignem multiplier increases to 150% of original. (Exceptional — dramatically accelerates Charge and Talent follow-up frequency.)
Build Guide
🔮 Best Relic / Echo Set
Divine-Querying Master Smith (4pc) — 2pc: Max HP +12%; 4pc: CRIT DMG +28% against DEF-reduced enemies and applies the "Comburent" buff to the whole team (+15% DMG for 2 turns) after activating DEF reduction. Perfectly aligned with his constant Balefire Bind DEF shred. Alternatives: Pioneer Diver of Dead Waters (4pc) for scaling CRIT benefits with debuff stacks; Longevous Disciple (4pc) for consistent CRIT Rate stacking from HP consumption. Planar: Bone Collection's Serene Demesne (Max HP +12%; CRIT DMG +28% when Max HP ≥ 5000) is best-in-slot; Inert Salsotto (CRIT Rate + Ultimate/FUA DMG) or Duran, Dynasty of Running Wolves (FUA teams) are strong alternatives.
⚔ Best Light Cone / Weapon
Signature: Reforged in Hellfire — increases Max HP, grants 20 Energy at the start of each wave, and applies the "Purgatory" debuff on Skill use (enemies take +30% CRIT DMG from the wearer; stacks with the follow-up CRIT DMG bonus for up to +60%). F2P / Budget: Lies Dance on the Breeze — +18% SPD and high-chance DEF shred via Bamboozle/Theft states; requires 28% Effect Hit Rate. Resolution Shines As Pearls of Sweat (S5, 4★) — Ensnare DEF reduction, requires 67% EHR. Before the Tutorial Mission Starts (4★ Nihility) — EHR and Energy regeneration against DEF-reduced enemies. Holiday Thermae Escapade — Vulnerability debuff stacking with his Ultimate effects. Along the Passing Shore — CRIT DMG and Mirage Fizzle debuff; stronger when playing him as a primary DPS rather than support.
📊 Substats Priority
👥 Best Teams
Acheron Core: Mortenax Blade + Acheron + Jiaoqiu + Hyacine (Zone auto-feeds Acheron's Ultimate gauge on every ally hit; satisfies Nihility requirement; Jiaoqiu stacks debuffs)
Acheron Budget: Mortenax Blade + Acheron + Tribbie + Gallagher (accessible sustain + RES PEN)
Ashveil Hypercarry: Mortenax Blade + Ashveil + Tribbie + Hyacine (Ashveil's high action frequency maximises Charge stacking; Tribbie adds Vulnerability + RES PEN)
Ashveil Alternative: Mortenax Blade + Ashveil + Sunday + Huohuo (Sunday advances Ashveil; Huohuo sustains low-HP Blade)
Feixiao FUA: Mortenax Blade + Feixiao + Tribbie + Hyacine (Feixiao's follow-up frequency rapid-fires Talent procs)
Feixiao Budget: Mortenax Blade + Feixiao + Ashveil + Gallagher (dual high-frequency attackers for Charge)
General Support: Mortenax Blade + Tribbie + Sparkle + Gallagher (flexible SP-neutral composition)
F2P Verdict
Limited banner character — no standard pool access. E0 is fully meta-relevant and the efficient base-case pull. His signature Reforged in Hellfire is a meaningful upgrade (Energy economy + team CRIT DMG) but not mandatory — Lies Dance on the Breeze or Resolution Shines As Pearls of Sweat (4★) are solid substitutes depending on playstyle. Critical caveat for F2P: Mortenax Blade deliberately operates near 1 HP during Infinite Fury; a reliable premium healer is not optional. Hyacine is best-in-slot; Luocha (standard 5★) is the most F2P-accessible top-tier substitute. Gallagher (free 4★) can sustain short content windows. His A4 Trace causes enemies to target him preferentially, making sustain investment non-negotiable.
Frequently Asked Questions
What does Mortenax Blade's Zone actually do?
Once deployed via his Ultimate, the Zone enters Infinite Fury state and causes every ally attack to automatically apply Balefire Bind to the hit enemy. Balefire Bind reduces enemy DEF by 30% and increases damage received by 50% for 2 turns — at zero SP cost. This passive application on every ally action is what makes him universally strong.
Does Mortenax Blade work well with Acheron?
He is considered one of Acheron's strongest ever partners. His Zone auto-applies a debuff (Balefire Bind) on every ally attack, continuously feeding Acheron's Crimson Knot generation and Ultimate gauge. He also satisfies the Nihility ally requirement for Acheron's major trace, enabling her full 75% ally Ultimate DMG boost via his A6 Trace.
Is Mortenax Blade dangerous to run due to low HP?
Yes — by design. During Infinite Fury he hovers near 1 HP after consuming his Max HP. His A4 Trace also makes enemies target him more often. A top-tier healer (Hyacine or Luocha) is non-negotiable. He does have a built-in survival mechanic: lethal hits while in Infinite Fury exit the state instead of killing him and restore 50% Max HP.
What is Mortenax Blade's relationship to the original Blade?
Mortenax Blade is an alternate form of Yingxing (Blade), the immortal Stellaron Hunter swordsman. This version appears in the Planarcadia storyline set within the dream-realm of the Aeon Aha. His original Wind/Destruction kit becomes a Fire/Nihility kit in this form, reflecting his role as a craftsman reborn through flame — 'ancient grudges ignited once more.'
Which Eidolons are worth pulling for Mortenax Blade?
E1 adds 20% All-Type RES shred while the Zone is active and extends Infinite Fury uptime after Talent procs — an efficient first upgrade. E2 converts ally Ultimates into Follow-Up ATKs with +75% FUA DMG, dramatically increasing Charge generation and team damage. E3 and E5 are level-only upgrades and not worth pursuing. E6 is exceptional (Charge on any HP loss or damage taken; boosted Tenax Per Ignem multiplier) but is a luxury investment.