Mortenax Blade is a 5-star Fire character on the Path of Nihility, and he plays two roles in one slot. Before his Ultimate, he works as a debuff support. After it, he deploys a Zone, enters the "Infinite Fury" state, and turns into a Max HP-scaling damage dealer who burns through his own health. Picking the right teammates comes down to one decision: do you want him amplifying a Nihility carry, enabling Follow-up attackers, or carrying the fight himself?
How Mortenax Blade's team role works
His Ultimate, Fornax Ex Corpore, inflicts "Balefire Bind" on all enemies, cutting their DEF by 30% and raising the damage they take by 50% for 2 turns. It then spends part of his Max HP to deploy a Zone. While that Zone is up, every ally deals 50% more damage from his "Heart, Refined ad Infinitum" trace.
The key team-building branch sits inside that same trace. If there is at least one other Nihility character on the team, all allies deal 75% more Ultimate damage. If there is no other Nihility unit, that bonus instead goes to Mortenax Blade's own damage. This single rule decides whether he is a support or a carry.
Acheron Nihility team (Ultimate amplification)
This is the setup that uses the Nihility branch of his trace. With Acheron and a second Nihility support on the field, the whole team picks up the 75% Ultimate damage bonus on top of the 50% Zone buff and the Balefire Bind DEF shred. Mortenax Blade stays in support mode, taunts enemies, and keeps debuffs flowing.
| Role | Unit | Why it fits |
|---|---|---|
| Main DPS | Acheron | Nihility carry whose damage rides on enemy debuffs and Ultimate output. |
| Support / Sub-DPS | Mortenax Blade | Zone, Balefire Bind, and the Nihility Ultimate buff. |
| Nihility debuffer | Pela or Silver Wolf | Stacks debuffs to feed Acheron and satisfies the second-Nihility condition. |
| Healer | Luocha or Huohuo | Keeps Mortenax Blade alive through HP drain. |
Feixiao Follow-up team
Mortenax Blade also revives Follow-up attack squads. His Eidolon 2 makes any ally Ultimate count as a Follow-up attack and raises Follow-up attack damage by 75%, which lines up directly with Feixiao. The Balefire Bind DEF reduction and the Zone's flat damage boost stack on top of her own kit.
| Role | Unit | Why it fits |
|---|---|---|
| Main DPS | Feixiao | Follow-up DPS that benefits from Balefire Bind and E2's Follow-up buff. |
| Support / Sub-DPS | Mortenax Blade | Provides the Zone, DEF shred, and a damage taken increase. |
| Damage amplifier | Robin | Team-wide damage and turn advance to push more attacks. |
| Healer | Gallagher or Huohuo | Sustains the team and Mortenax Blade's HP cost. |
Note: the 75% Follow-up boost comes from his Eidolon 2. At E0 you still get the Zone, the debuffs, and Robin's amplification, so the squad works, just with less Follow-up scaling.
Mortenax Blade hypercarry team
If you have no other Nihility unit, his trace points the 75% bonus at his own damage, so he can headline the team. In "Infinite Fury" his CRIT Rate goes up by 20% and CRIT DMG by 60%, and his enhanced Ultimate, Tenax Per Ignem, hits all enemies for a large multiple of his Max HP. Surround him with buffers and a strong healer.
| Role | Unit | Why it fits |
|---|---|---|
| Main DPS | Mortenax Blade | Solo Nihility carry; gains the 75% personal damage bonus. |
| Buffer | Sunday or Bronya | Turn advance and damage buffs to speed up his rotation. |
| Buffer / amplifier | Tribbie or Robin | RES PEN and added team damage on top of the Zone. |
| Healer | Hyacine or Luocha | High, consistent healing to offset HP consumption. |
What every Mortenax Blade team needs
Across all three setups, a few requirements stay constant. Get these right and the squad holds together regardless of who you put in the carry slot.
- One reliable healer. He pays HP for his Skill and Ultimate, so the Zone collapses fast without sustain. His A4 trace also raises incoming healing by 50% while the Zone is up, which makes healers more effective on him.
- A second Nihility unit, or none at all. Commit to the branch you want. Two Nihility units turns on the team-wide Ultimate buff; a single Nihility build hands the bonus to Mortenax Blade himself.
- Max HP scaling on Mortenax Blade. Every one of his attacks scales off Max HP, so build him for HP, CRIT, and survivability rather than ATK.
How to confirm your team is working
You will know the comp is set up correctly when you see the Balefire Bind icon on enemies after his Ultimate, the Zone indicator active on the field, and "Infinite Fury" listed under Mortenax Blade with its fixed-SPD countdown on the action order. While the Zone is live, his Skill unlocks, and his ally damage buff applies.
The most common reason a team underperforms is the Zone ending early. That happens when his HP runs out, and he leaves "Infinite Fury," or when the countdown's turn arrives and dispels the Zone. Keep your healer's turns frequent, and use his charge-fueled extra Skill to keep pressure up before the countdown lands.
The flexible takeaway is that Mortenax Blade fits almost anywhere you have a healer to spare. Slot him next to Acheron for Ultimate teams, behind Feixiao for Follow-up damage, or front and center as a self-sufficient Fire carry, and his Zone, debuffs, and HP-scaling damage do the rest.