The best Black Swan build in Honkai: Star Rail centres around buffing the fortune teller’s DoT damage. This five-star character is laser-focused around dealing DoT—or damage-over-time—and supporting teams that also like to slowly chip away at enemies with wind shear, bleed, burn, or shock.
Black Swan stacks the Arcana effect on enemies, dealing wind damage to them each turn, but she has a chance to inflict additional stacks on enemies who already have DoT effects. The more Arcana she stacks, the stronger her damage, plus she gets additional effects through her talent, such as ignoring 20% DoT defense when damaging enemies.
This means that if you really want Black Swan to shine, you’ll whack her in a team that can apply the largest variety of DoT effects possible. Here’s the best Honkai: Star Rail Black Swan build, plus all of her skills, eidolons, and ascension materials.
The best Black Swan build
Black Swan is a character focused around dealing DoT damage and gaining added benefits when placed in a team capable of applying lots of different DoT types. This is because the Arcana effect she inflicts gains extra stacks against enemies who already have DoT, buffing the wind damage she deals to them at the start of each turn, plus additional effects.
- Light Cone: Reforged Remembrance or Eyes of the Prey
Black Swan’s five-star Reforged Remembrance Light Cone is arguably the best option for her. It boosts effect hit rate by 40%, which in turn buffs her damage once you unlock the Candleflame’s Portent bonus ability. This Light Cone also adds a stackable resource called Prophet, which accumulates when the wearer deals damage to an enemy afflicted with DoT. Each stack increases attack by 5% and allows DoT damage to ignore 7.2% of a target’s defence.
That said, you can only gain one stack per DoT that the enemy you damage has, meaning this Light Cone will only shine if you’re using other party members to apply DoT effects also. This is the way you should use Black Swan since she inflicts extra Arcana, and so damage, when she hits enemies afflicted with a variety of DoT types. If you’re using Black Swan in a team lacking the means to apply DoT, then Kafka’s Patience is All You Need might be a better option if you already have it.
This Light Cone increases damage by 24% and speed by 4.8% when you attack, but more importantly, it inflicts Erode on targets, which makes them shocked at the start of their turn. This would be an effective way of allowing Black Swan to deal additional DoT and so stack more Arcana on enemies. If you’re looking for a four-star Light Cone option, then Eyes of the Prey is your best bet for its effect hit rate and DoT boost. Though less ideal, you could also use Before the Tutorial Mission Starts if you grabbed it during the Silver Wolf event.
- Relics: Prisoner in Deep Confinement (Four-pieces equipped)
Black Swan’s relic choice is pretty straightforward—four pieces of Prisoner in Deep Confinement for the 12% attack boost and the stacking 6% defense reduction on targets with DoT, up to three different types. If you’re already using the Reforged Remembrance Light Cone, this effectively stacks the same effect for more defense reduction.
For your primary stats, you’ll want effect hit rate on the body to maximise the extra damage you’re getting from the Candleflame’s Portent bonus ability, plus speed on the boots is pretty standard for making sure Black Swan gets the chance to act often.
| Body | Effect hit rate |
| Feet | Speed |
- Planar Ornaments: Pan-Cosmic Commercial Enterprise (Two-pieces equipped)
The Planar Ornaments for Black Swan are also simple, further bolstering effect hit rate with Pan-Cosmic Commercial Enterprise, plus adding an attack boost based on 25% of effect hit rate, up to 25%. In terms of primary stats, I recommend an attack boost on the Link Rope and wind damage boost on the Planar Sphere to maximise the devastating effect of those Arcana stacks.
| Planar Sphere | Wind damage boost |
| Link Rope | Attack |
Black Swan abilities and Eidolons
Here are Black Swan’s abilities for leveling skills and the Eidolons you can get by rolling extra copies of her—as always, thanks to Honey Hunter for the details:
| Basic attack | Percipience, Silent Dawn: Deals wind damage equal to 78% of Black Swan’s attack to a single target, with a 74% chance of inflicting one stack of Arcana. If the target has wind shear, bleed, burn, or shock, each respectively has a 74% chance of inflicting a further stack of Arcana. |
| Skill | Decadence, False Twilight: Deals wind damage equal to 112.5% of Black Swan’s attack to a single target and any adjacent enemies. Also has a 100% chance to inflict one stack of Arcana, and a 100% chance of reducing defense by 23.8% for three turns. |
| Talent | Loom of Fate’s Caprice: Every time an enemy receives a DoT at the start of a turn, there is a 72.5% chance to inflict a stack of Arcana. While inflicted with Arcana, targets take wind damage equivalent to 300% of Black Swan’s attack at the start of each turn. Each stack of Arcana increases this by 15%, then Arcana resets to one stack. Arcana can stack up to 50 times. Black Swan triggers additional effects based on Arcana stacks. Three or more deals wind DoT equal to 225% of her base attack, with a 72.5% chance of inflicting Arcana on adjacent targets, while seven or more allows the DoT to ignore 20% of the target and adjacent targets’ defense. |
| Ultimate | Bliss of Otherworld’s Embrace: Deals wind damage equal to 144% of Black Swan’s attack to all enemies. Also inflicts Epiphany on enemies for two turns. Enemies afflicted by Epiphany take 30% more damage on their turn, and their Arcana effect is regarded as wind shear, bleed, burn, or shock. When their Arcana effects trigger, the stacks will not reset to one. This effect is possible once per enemy unless Epiphany is re-applied. |
| Bonus ability | Viscera’s Disquiet: When using Black Swan’s skill to hit an enemy that has wind shear, bleed, burn, or shock, each of these debuffs has a 65% chance of inflicting one extra stack of Arcana. |
| Bonus ability | Goblet’s Dredges: There is a 65% chance to inflict one stack of Arcana when a target enters battle. Every time an enemy receives a DoT from an attack, there is a 65% chance for them to be inflicted with one stack of Arcana, stacking up to three times from any single attack. |
| Bonus ability | Candleflame’s Portent: Increases this unit’s damage by an amount equal to 60% of effect hit rate, up to a maximum damage increase of 72%. |
| Technique | From Façade to Vérité: Has a 150% chance to inflict enemies with one stack of Arcana at the start of the next battle. For every stack inflicted, inflict a further stack on that target with a decreasing success chance at 50% of the previous. |
| Seven Pillars of Wisdom | While Black Swan is active in battle, enemies afflicted with wind shear, bleed, burn, or shock will have their corresponding wind, physical, fire, or lightning resistance reduced by 25%. |
| Weep Not For Me, My Lamb | When an enemy target afflicted with Arcana is defeated, there is a 100% base chance of inflicting six stacks of Arcana on adjacent targets. |
| As Above, So Below | Skill and talent plus two levels, up to a maximum of 15. |
| In Tears We Gift | While inflicted with Epiphany, enemies have their effect resistance reduced by 10%. At the start of their turn or when they get defeated, Black Swan regenerates eight energy. This energy regeneration effect can only trigger up to one time while Epiphany lasts, or until an enemy is inflicted with Epiphany again. |
| Linnutee Flyway | Ultimate plus two levels up to a maximum of 15, and basic attack plus one, up to a maximum of 10. |
| Pantheon Merciful, Masses Pitiful | When enemy targets get attacked by Black Swan’s allies, Black Swan has a 65% base chance of inflicting one stack of Arcana on the target. Each time Black Swan inflicts Arcana on an enemy target, there is a 50% fixed chance to additionally increase the number of Arcana stacks afflicted this time by one. |
Black Swan Ascension materials
Here’s what you’ll need to ascend Black Swan, not including XP materials:
- 15 Extinguished Cores
- 15 Glimmering Cores
- 15 Squirming Cores
- 65 Ascendant Debris
- 300,000 credits (approx)
Extinguished Cores and their higher tier variants are easy to get through sending characters on assignment, or via defeating Fragmentum monsters in any other activities. Ascendant Debris comes from the Stagnant Shadow: Shape of Celestial in the Alchemy Commission area of the Xianzhou Luofu. Lastly, you can get credits by doing just about anything, but if you need them fast, the Golden Calyx: Bud of Treasures is your best bet.