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Eternal Waltz
April 29, 2026 at 03:18 PM
Added Arc weapon icon image
Eternal Waltz is an unusual S-Class Arc that rolls HP% as its main substat instead of the usual ATK line, making it the only S-Class Arc built for HP-scaling builds. Its Arachne passive turns the extra HP pool into offensive pressure by boosting Mental DMG for ten seconds every time the wearer casts an Ultimate.

Eternal Waltz is a 5★ S-Class Synthesis-type Arc in Neverness to Everness. It rolls a base 424 ATK at Level 80 with a 41.2% HP% substat. The primary skill, Arachne, defines its role across rotations and team compositions.
"Dance to the beat, feel the dizzying sensation as if the world is ending, until forever!"
The flavor text sets the Arc's tone and gives designers a quick lens on how the Arachne passive is meant to feel in play.
The Arachne passive provides the following effect at Refinement Rank 1: Increases Max HP by 20%. Increases Mental DMG dealt by 10% for 10s after the wearer casts an Ultimate.
Refinement ranks raise these values without changing the trigger conditions. The table below lists the per-rank scaling.
Level | Max HP | Mental DMG (10s after Ultimate) |
|---|---|---|
L1 | +20% | +10% |
L2 | +23% | +12% |
L3 | +26% | +14% |
L4 | +29% | +16% |
L5 | +32% | +18% |
Reaching Level 80 with full access to the Arachne passive requires six ascension breakthroughs. Each phase raises the level cap and unlocks the next refinement condition. The costs are fixed per Arc and do not scale with refinement rank.
Phase | Level Cap | Gold | Materials |
|---|---|---|---|
Phase 1 | Lv.30 | 20,000 | |
Phase 2 | Lv.40 | 40,000 | Flavorless Cold Dessert x10, Fading Silhouette x10 |
Phase 3 | Lv.50 | 60,000 | |
Phase 4 | Lv.60 | 80,000 | Plain Cold Dessert x12, Blurred Silhouette x12 |
Phase 5 | Lv.70 | 100,000 | |
Phase 6 | Lv.80 | 120,000 | Special Cold Dessert x12, Chaos Silhouette x12 |
The listed compatible characters share the Arc's core synergy. Any character can equip any Arc regardless of element or skill fit, but these characters gain the full value of the Arachne passive thanks to their kits and scaling.
Character | Element | Rarity | Why It Fits |
|---|---|---|---|
5★ | S-Class Incantation DPS from ETD-4, whose spellcasting rotation benefits from consistent ATK and damage multipliers; a natural fit for the Arachne payoff. | ||
5★ | S-Class Psyche tank whose damage-redirect kit scales with survivability and sustained uptime; a natural fit for the Arachne payoff. | ||
4★ | A-Class Incantation butler whose shield- and buff-based support rotation pairs well with defensive and offensive Arcs alike; a natural fit for the Arachne payoff. |
Eternal Waltz is acquired through the standard Arc acquisition methods in Neverness to Everness. S-Class Arcs can appear in the gacha system and its pity guarantees, in specific shop rotations, and in limited event reward tracks.
Method | Details |
|---|---|
Miracle Box 5★ tiles | S-Class Arcs appear as guaranteed 5★ tile payouts on the Arc gacha board. |
Arc banner pity | Soft pity at 60 pulls, hard pity at 80 pulls. The featured S-Class Arc has a 25% chance at soft pity. |
Long-term currency shops | Select S-Class Arcs rotate through the Tri-Keys shop and limited event storefronts. |
Confirm your chosen character's rotation lines up with the Arachne trigger before investing refinement materials. An Arc whose condition you cannot reliably fire is worth less than a B-Class Arc you activate every rotation.
At Refinement Rank 1 the values in the passive table are baseline. Early ranks give the biggest jumps; the last couple of ranks are smaller gains and usually not worth duplicating a 5★ Arc unless the character is a dedicated main DPS.
Pair Eternal Waltz with Synthesis-aligned Drive Blocks and KongMu Gear. Matching element on support gear stacks multiplicatively with the Arc's passive.
Keep the ascension materials in mind when planning farming routes. The final two phases jump from a 6x to a 12x requirement, which is often the real blocker for hitting Level 80.
Review the Compatible Characters table before equipping. Element mismatch still works, but the biggest multipliers assume the passive's trigger and your character's rotation are synchronized.
Field | Value |
|---|---|
Rarity | S-Class (5★) |
Arc Type | Bose |
Base ATK (Lv. 80) | 424 |
HP% (Lv. 80) | 41.3% |
At base refinement (R0), the passive reads: Increases Max HP by 20%. Increases Mental DMG dealt by 10% for 10s after the wearer casts an Ultimate.
The passive scales across five refinement levels (R1 to R5). Refinement is achieved by combining duplicate copies of the same Arc, with each refinement adding to the headline numbers. At R5: Max HP +32%, Mental DMG +18%.
The Eternal Waltz is a Bose-type Arc. Espers with Bose Arc compatibility can equip it; the recommended 3-character roster below covers the highest-impact pairings:
Esper | Rarity | Element |
|---|---|---|
S-Class | Incantation | |
S-Class | Psyche | |
A-Class | Incantation |