Acheron vs Mortenax Blade

• Burst kit built around one Ultimate: Rainblades into Stygian Resurge clear packs while ignoring Toughness type and applying all-type RES shred for the whole sequence—so she stays viable even when Lightning is not on the weakness list.
• Trace A4’s 1.6× personal damage multiplier (with two other Nihility allies) sits outside normal DMG% stacking, so her ceiling does not depend on borrowing Robin, Ruan Mei, or Sparkle from the other Memory of Chaos side.
• Debuff teammates double as fuel—every ally application feeds Slashed Dream and Crimson Knot—so well-built Nihility cores keep Ultimates cycling in MoC and Pure Fiction without Energy-battery supports.

• Full A4 scaling wants three Nihility characters on the roster (E2 lowers that to two paths total); swapping in Harmony for the second Nihility slot only works with well-built supports and still forgoes part of her multiplier.
• Most of her damage is booked into one Ultimate—Rainblades that remove too few Crimson Knot stacks, or hit the wrong enemy in multi-target fights, can waste the bulk of the rotation.
• Basic ATK and Skill ratios are modest compared with many newer 3.x carries; she climbs tiers through debuff-fed stacking, type-agnostic break, and RES shred during Ult—not steady single-target Skill spam.

• Ultimate “Fornax Ex Corpore” spends HP as a deliberate self-damage cost—level this before polishing filler traces.
• Skill “A Rain of Blades Seals Fate” spends HP as a deliberate self-damage cost—the rotation wants controlled self-damage, not panic healing that cancels the state.
• Talent “All Karma Comes Due” fires Follow-Up ATKs off ally Basics—damage keeps flowing even when Mortenax Blade is not the active turn.

• Follow-Ups from “All Karma Comes Due” need allies who actually Basic ATK on schedule—freeze/CC on the team stalls Mortenax Blade’s off-turn damage.
• HP-spend skills mean Mortenax Blade can soft-lock if sustain is weak or if a healer tops them up at the wrong time and breaks a low-HP / Charge condition.
• Spamming “A Rain of Blades Seals Fate” every turn without watching Skill Points strands the rest of the team—Mortenax Blade is often the SP sink.

Light Cone

Along the Passing Shore

Relics

Pioneer Diver of Dead Waters (4pc) + Izumo Gensei and Takama Divine Realm (2pc)

Body

CRIT Rate%

Feet

ATK%

Sphere

ATK% / Lightning DMG%

Rope

ATK%

Substats

CRIT Rate ≥ CRIT DMG > ATK% > SPD (only if using SPD-set tech)

Light Cone

Reforged in Hellfire

Relics

Pioneer Diver of Dead Waters (4pc) + Pan-Cosmic Commercial Enterprise (2pc)

Body

Effect Hit Rate

Feet

SPD

Sphere

Fire DMG%

Rope

ATK%

Substats

EHR (to threshold) > SPD > ATK% / CRIT