Mortenax Blade is the Fire Nihility version of Blade, and he slots into almost any roster because he can play two roles at once. He buffs the team with heavy debuffs while still dealing real damage of his own, and his HP-scaling kit makes him both a sub-DPS and a durable support. The trick to building around him is feeding his Charge engine and keeping his Zone active, which is where his teammates come in.
How Mortenax Blade fits into a team
Everything starts with his Ultimate. It inflicts Balefire Bind on every enemy, cutting their DEF by 30% and raising the damage they take by 50% for two turns, then deploys a Zone that puts him into the Infinite Fury state. While that Zone is up, his teammates do the heavy lifting for his resource loop.
Whenever an ally attacks an enemy during the Zone, that enemy gets Balefire Bind and Mortenax Blade gains 1 Charge. At 9 Charge he restores 25 Energy and fires an extra Skill that counts as a Follow-Up attack and costs no HP. That single mechanic is why fast, multi-hit, and Follow-Up teammates are his best friends. The more often allies swing, the more debuffs land and the more bonus Skills he throws out.
His A6 trace, Heart, Refined ad Infinitum, increases ally damage by 50% while the Zone is active. If there's another Nihility character on the team besides him, allies also gain 75% Ultimate damage. If there isn't, that 75% boost is funneled into his own damage instead. That conditional is the single biggest factor in deciding who you put next to him.
Best Mortenax Blade synergies
A handful of characters stand out as repeat picks across his strongest lineups. Each one either generates Charge quickly, stacks more amplification, or feeds his HP-scaling needs.
| Character | Why they work |
|---|---|
| Acheron | His constant debuff application speeds up her Ultimate generation, and he satisfies her Nihility requirement while handing the team extra Ultimate damage. She ends up casting her Ultimate multiple times per rotation. |
| Ashveil | A high-frequency Follow-Up attacker who rapidly charges Blade's Talent Skill. He happily shares the DPS slot, and Blade returns the favor with debuffs. |
| Feixiao | Her high action count quickly builds Blade's Charge, and his DEF reduction plus Vulnerability sharply raises her damage. |
| Tribbie | An HP-scaling amplifier offering Vulnerability and All-Type RES PEN at a low Skill Point cost, and she triggers plenty of Follow-Up attacks of her own. |
| Hyacine | Raises the whole team's Max HP and heals off it, directly improving Blade's and Tribbie's HP-based output. |
Mortenax Blade team compositions
None of these are the only correct answer, and leaving a team off the list doesn't mean it's weak. They cover the main archetypes he supports.
| Team | Core idea |
|---|---|
| Blade + Acheron + Cipher + Huohuo | Acheron hypercarry. Blade and Cipher both feed debuffs to spam her Ultimate; Huohuo handles ATK buffs and energy. |
| Blade + Acheron + Tribbie + Gallagher | Acheron variant with Tribbie's amplification and a low-maintenance sustain. |
| Blade + Acheron + Jiaoqiu + Hyacine | Debuff-heavy Acheron line with HP-based sustain from Hyacine. |
| Blade + Ashveil + Tribbie + Hyacine | Dual-DPS Follow-Up team where everyone except Ashveil scales with HP and stacks Follow-Up triggers. |
| Blade + Feixiao + Tribbie + Hyacine | Feixiao Follow-Up carry boosted by Blade's debuffs and Tribbie's amplification. |
| Blade + Feixiao + Ashveil + Gallagher | Double Follow-Up DPS that keeps Blade's Charge filling constantly. |
| Blade + Ashveil + Sunday + Huohuo | Ashveil carry with Sunday's action advancement and energy support. |
| Blade + Tribbie + Sparkle + Gallagher | Blade-as-DPS build using Sparkle's Skill Point economy and crit support. |
Blade + Acheron + Cipher + Huohuo
This is the team Mortenax Blade was practically built for. While his Zone is live, every ally hit on an enemy reapplies Balefire Bind, and enemies attacking Blade get it too. That steady debuff stream regenerates Acheron's Ultimate, so she fires it several times across one rotation while soaking up his DEF reduction, Vulnerability, and ally damage buffs.
Cipher fills Acheron's required second Nihility slot, records team damage, and adds another debuff to push her DPS higher. Huohuo rounds it out with an ATK% buff and energy regeneration that also helps Blade keep his Ultimate online. If you'd rather lean into HP scaling, swapping Huohuo for Hyacine raises Blade's Max HP instead.
Blade + Ashveil + Tribbie + Hyacine
Ashveil is always happy to share the field with a second damage dealer, and Mortenax Blade is one of the best he can pair with. Ashveil's rapid attacks fill Blade's Charge fast, triggering his free Follow-Up Skills, while Blade's Ultimate Zone amplifies the whole squad.
Tribbie and Hyacine glue the team together through HP scaling. Tribbie boosts her own HP based on the team's total Max HP and supplies amplification, while Hyacine raises everyone's Max HP and heals off it. That feeds directly into Blade's and Tribbie's damage. A useful slotting rule for this comp is to place the ATK-scaling DPS first, a squishier unit second, your tanky unit third, and Blade in the fourth slot.
Feixiao and Follow-Up teams
Feixiao is another natural carry next to Mortenax Blade. Her high action frequency keeps his Charge climbing, which means more extra Skills, and his debuffs noticeably raise her damage. Pairing her with Tribbie and Hyacine gives a clean HP-friendly support core, while running her alongside Ashveil and Gallagher doubles down on Follow-Up triggers and keeps Blade's loop firing almost every turn.
The throughline across all of these is simple. Give Mortenax Blade a DPS that attacks often, satisfy Acheron's Nihility check when she's on the team, and add one amplifier and one sustain that play well with his HP scaling. Do that and his Zone stays up, his Charge keeps flowing, and the rest of the team gets to cash in on his debuffs.