Acheron is a 5-star Nihility character in Honkai: Star Rail who wields the power of Lightning DMG. Empowered by debuff synergy, she excels at overwhelming enemies through a strategic buildup of status effects before striking with an Ultimate that wipes the field clean.
What makes Acheron stand out is her Slashed Dreams mechanic — a unique energy system that rewards players for clever use of debuffs. In this guide, we’ll walk you through everything you need to bring out Acheron’s full potential, including how her kit works, the best Eidolons, recommended Relic sets and stat priorities, Light Cone recommendations, and stat optimization strategies.
Acheron’s Kit and Eidolons
Acheron is a powerful Nihility character who thrives on debuffing enemies and unleashing devastating AoE Lightning damage. Her kit revolves around applying stacks of Crimson Knot on enemies by casting debuffs on enemies. Each stack of Crimson Knot releases Electric DMG to the entire enemy party when removed. You remove Crimson Knot stacks by activating Acheron’s Ultimate.
Acheron’s Moveset
| Attack Type | Name | Description |
|---|---|---|
| Basic ATK | Trilateral Wiltcross | Deals Lightning DMG equal to 50% of Acheron’s ATK (single target) |
| Skill | Octobolt Flash | Deals Lightning DMG equal to 80% of Acheron’s ATK (single target). Gains 1 Slashed Dream. Inflicts 1 Crimson Knot. |
| Ultimate | Slashed Dream Cries in Red | Unleashes Rainblade 3 times then Stygian Resurge 1 time for Lightning DMG up to 223.2% of Acheron’s ATK to main target and up to 180% to other targets (AoE). Stygian Resurge deals Lightning DMG equal to 72% of Acheron’s ATK to all enemies. Removes Crimson Knots. |
| Talent | Atop Rainleaf Hangs Oneness | If 9 Slashed Dreams have been accumulated, unlocks Acheron’s Ultimate. Any debuffs applied to enemies increase Slashed Dream by 1 point and apply Crimson Knot to the target. |
| Technique | Quadrivalent Ascendance | Strikes the enemy. Deals Lightning DMG equal to 200% of Acheron’s ATK and reduces Toughness of all enemies. (Multiple Targets) |
Acheron’s Ascensions
| Ascension Level | Effect Name | Effect Description |
|---|---|---|
| A2 | Red Oni | Starts battle with 5 points of Slashed Dream and applies 5 Crimson Knot to a random enemy. |
| A4 | The Abyss | Acheron’s ATK, Skill, and Ultimate DMG increases for every other Nihility character in the party. |
| A6 | Thunder Core | When Rainblade hits an enemy with Crimson Knoght, Acheron deals 30% more DMG. Can stack up to 3 times. |
Acheron’s Eidolons
| Eidolon Level | Eidolon Name | Description |
|---|---|---|
| E1 | Silenced Sky Spake Sooth | CRIT Rate rises 18% when dealing DMG to enemies with debuffs. |
| E2 | Mute Thunder in Still Tempest | Reduces the number of Nihility characters required to reach the highest possible effect from The Abyss (Ascension 4 Effect). |
| E3 | Frost Bites in Death | Ultimate Lv. +2 (up to Lv. 15), Basic ATK Lv. +1 (up to Lv. 10) |
| E4 | Shrined Fire for Mirrored Soul | When enemy targets enter combat, inflicts Ultimate DMG Vulnerability, increasing the DMG they take from Ultimates by 8%. |
| E5 | Strewn Souls on Erased Earths | Skill Lv. +2 (up to Lv. 15), Talent Lv. +2 (up to Lv. 15) |
| E6 | Apocalypse, the Emancipator | Increases the All-Type RES PEN for Ultimate DMG by 20%. DMG from Basic ATK and Skill are treated as Ultimate DMG. When breaking Weaknesses, triggers Lightning Weakness Break effect. |
Best Light Cones for Acheron
Every part of Acheron’s kit is made to build up her Ultimate. Because of this, you want to equip her with a Light Cone that can greatly boost her Ultimate’s DMG.
BEST – Along the Passing Shore
This Light Cone buffs CRIT DMG by up to 60%, but the bigger deal is the Mirage Fizzle debuff it applies on any target that its wearer attacks. Targets with Mirage Fizzle take up to 40% extra DMG from Ultimates, making this Light Cone the very best choice for an Ultimate-focused character like Acheron.
Crucially, Mirage Fizzle counts as a debuff, so using a Skill with this equipped increases your Slashed Dream count as well as adds a stack of Crimson Knot to its target.
Alternative – Incessant Rain
Incessant Rain boosts DMG against enemies with three or more debuffs. Using a Basic ATK, Skill, or Ultimate applies Aether Code on the target, which causes them to receive up to 20% increased DMG for a turn.
Best Relics for Acheron
BEST – Pioneer Diver of Dead Waters
Pioneer Diver of Dead Waters is the best Relic set for characters whose kits revolve around heavy use of debuffs, like Acheron. The complete set makes its wearer deadly effective against enemies with lots of debuffs by boosting DMG, CRIT Rate, and CRIT DMG. You should get at least 2 pieces benefit from the 12% DMG boost against enemies with debuffs. Don’t stop there, though—the CRIT Rate and CRIT DMG buffs you get from the full set are exactly what Acheron is looking for.
Main/Substats
- Body (Crit DMG or Crit Rate): As with any hard-hitting main, you can’t go wrong with some extra Crit. If your current Crit Rate is below 70%, prioritize Crit Rate, otherwise go for Crit DMG.
- Feet (ATK% or Speed): Unlike some characters, hitting Speed breakpoints isn’t as crucial on Acheron. You want to give other characters turns between Acheron’s so you can apply debuffs and more easily time Crimson Knot stacks and your Ultimate.
- Planar Sphere (Lightning DMG): Boost Acheron’s Ultimate by buffing up her Lightning DMG.
- Link Rope (ATK%): More is always better.
- You want a Crit Rate between 70–80% with a Crit DMG of 160–200%.
How to Play Acheron
To play Acheron effectively, follow this loop:
- Apply debuffs constantly — use her skill, her teammates’ debuffs, and gear that adds extra debuffs.
- Build Slashed Dreams through stacking debuffs — this charges her Ultimate.
- Stack Crimson Knots on enemies as you debuff them.
- Unleash the Ultimate when Slashed Dreams are full — this removes all Crimson Knots and blasts enemies with massive Lightning AoE damage.
The more debuffs and Crimson Knots you build before using her Ultimate, the bigger the payoff.
