Xingqiu & Yelan ER: Double Hydro Guide

Why Xingqiu and Yelan Together?

Xingqiu provides consistent Hydro application, damage reduction, and minor healing; Yelan adds ramping damage and a party-wide DMG buff. Together they solve each other's energy problems: Hydro Resonance increases the entire team's ER by 30%, and every Hydro particle either of them generates can be caught by the other. The duo is the cleanest example in the game of two characters making each other cheaper.

This guide breaks down each character's exact energy profile, shows the math behind the common breakpoints, and gives you tables you can apply directly to your build.

Xingqiu's Energy Profile

• Burst cost: 80 Energy, 20-second cooldown
• Skill: Guhua Sword: Fatal Rainscreen — 5 Hydro particles guaranteed per cast, 21-second cooldown
• C6: restores 3 flat Energy when enhanced rain swords hit (flat energy ignores ER%)
• Best energy weapon: Sacrificial Sword — double skill proc doubles his particle generation

Worked example (Sacrificial Sword double proc): 10 Hydro particles caught on-field by Xingqiu = 10 × 3.0 = 30 Energy. Required ER = (80 ÷ 30) − 1 = 167%. That matches the accepted 170–190% solo range — the extra ER covers rotations where Sac fails to reset and catches that miss.

Worked example (no Sacrificial): one cast, 5 particles = 15 Energy. Required ER = (80 ÷ 15) − 1 = 433% — impossible. A solo Xingqiu without Sacrificial Sword, Favonius Sword, or a second Hydro character simply cannot burst every rotation, no matter the artifacts. This is why his weapon choice is part of his energy build, not separate from it.

Yelan's Energy Profile

• Burst cost: 70 Energy, 18-second cooldown (cheaper than Xingqiu's 80)
• Skill: Lingering Lifeline — 4 Hydro particles per cast, 10-second cooldown (two casts per rotation)
• C1: grants a second Skill charge — roughly halves her ER requirement
• Best energy weapons: Favonius Warbow (team battery) or Elegy for the End

Worked example (C0, Favonius Warbow): two skill casts per 20-second rotation = 8 Hydro particles. Caught on-field: 8 × 3.0 = 24 Energy. Required ER = (70 ÷ 24) − 1 = 192%. With Favonius procs adding 12 flat team Energy, the practical range settles at 180–200% — consistent with the table below.

Worked example (C1): three skill casts = 12 particles = 36 Energy. Required ER = (70 ÷ 36) − 1 = 94%. Even accounting for imperfect catches, C1 Yelan lands around 140–170%, freeing her sands and substats for CRIT — the single biggest constellation upgrade to her build.

ER Breakpoints by Configuration

Solo Xingqiu (no Yelan, no second Hydro)

Weapon	ER Target	Why
Sacrificial Sword (R3+)	170–190%	Reliable double proc = 10 particles
Sacrificial Sword (R1)	190–210%	Double proc less reliable
Favonius Sword	180–200%	Self-battery via neutral particles
Lion's Roar / Harbinger of Dawn	200–240%	No ER substat, no double proc — expensive

Solo Yelan (no Xingqiu, no second Hydro)

Weapon	ER Target	Why
Favonius Warbow	180–200%	Skill particles + Favonius procs
Elegy for the End	200–220%	55.1% ER substat covers part of the gap
Aqua Simulacra	220–260%	0% ER substat — ER Sands mandatory
C1 + Favonius	140–170%	Second charge = 3 casts per rotation

Double Hydro (Xingqiu + Yelan together)

Character / Weapon	ER Target	Why
Xingqiu (Sacrificial)	140–160%	+30% Hydro Resonance + shared particles
Xingqiu (non-Sac)	160–180%	Yelan's particles subsidize his 80 cost
Yelan (Favonius)	140–170%	Resonance + Xingqiu's 5-particle skill
Yelan (Elegy)	170–190%	Damage weapon, still subsidized
Yelan (Aqua)	180–210%	0% ER substat; resonance does heavy lifting

The pattern is the lesson: adding Yelan to Xingqiu (or vice versa) cuts 30–50% ER off both, because Hydro Resonance stacks with shared same-element particles. Whatever you save on ER sands and substats goes directly into CRIT and HP rolls.

Artifact and Substat Priorities

• Xingqiu: Emblem of Severed Fate; ER Sands until breakpoint, then ATK%/Hydro goblet; CRIT circlet. At 180% ER, Emblem adds +20% Burst DMG — his ER is partially damage.
• Yelan: Emblem (burst-focused) or 2pc/2pc HP sets; HP% Sands once your ER target is met through substats + weapon; ER Sands otherwise. Yelan converts HP to damage, so every ER roll you avoid is a HP or CRIT roll you keep.
• Breakpoint rule: meet your team's ER target first, then maximize damage stats. A 150% Yelan with 35k HP out-damages a 220% Yelan with 28k HP in every rotation where her Burst is up on time.

Sample Double-Hydro Rotation (20 Seconds)

Energy flows correctly when the catch order is planned:

1. Yelan E (4 Hydro particles) → catch on Yelan on-field, or swap to Xingqiu if he is the one short
2. Yelan Q → swap
3. Xingqiu E → Q (5 particles, or 10 with Sacrificial double proc) → catch on Xingqiu
4. Driver takes the field; the duo's off-field damage and Yelan's dice tick through the rotation
5. Yelan E again (second cast, 10s CD) → catch on whoever needs it most

With Hydro Resonance (+30% ER) and both characters feeding each other same-element particles, the rotation self-sustains at the "Double Hydro" ER values above. The common failure is a driver (Raiden, Hu Tao, Neuvillette) catching all the Hydro particles — a waste, because the driver doesn't need them and the duo does.

Xingqiu C6 vs Yelan C1: Which Constellation First?

• Xingqiu C6 restores 3 flat Energy per enhanced rain sword hit — roughly 9–12 Energy per rotation, plus a significant damage boost. It lowers his ER need by ~15–20% and is a generalist upgrade to any Hydro team.
• Yelan C1 adds a second Skill charge: 4 extra Hydro particles per rotation and ~35–45% less ER pressure on her (140–170% comfort). If you own Aqua Simulacra, C1 is the constellation that makes it playable.

For the duo's energy economy specifically, Yelan C1 saves more ER because it multiplies her generation. Xingqiu C6 is the better all-rounder if you use him in multiple teams. Most players on a budget: C6 Xingqiu (free from banners over time) + Favonius Yelan is the strongest F2P combination — no ER issues at 170–190% on both.

Frequently Asked Questions

Is Hydro Resonance really +30% ER for the whole team?

Yes — the Hydro Resonance effect raises all party members' ER by 30% and is fully multiplicative with other ER sources. It is the strongest energy resonance in the game.

Xingqiu or Yelan first in double Hydro?

Both benefit, but Yelan benefits more: her lower cost (70 vs 80) and two skill casts per rotation mean she reaches comfort breakpoints with less investment, while Xingqiu still wants Sacrificial Sword for his double proc.

Does Xingqiu C6 remove the need for ER?

No, but it reduces it: 3 flat Energy per enhanced rain sword hit adds up to ~9–12 Energy per rotation, worth roughly 15–20% ER. He still wants 140%+ in double Hydro.

Calculate Your Exact Double-Hydro ER

The tables give you ranges; your actual rotation is unique. ER QuickCalc simulates your exact team — weapon refinements, constellations, catch order, Favonius procs — and returns precise ER targets for both Xingqiu and Yelan. Optimize the pair together, and spend every saved roll on damage.