HSR V3.4 Sunday Build Guide: Relic, Light Cone & Teams

Sunday returns in Version 3.4, and became one of Phainon's best teammates! As the ultimate single-target buffer, he slots into ANY hypercarry team with instant action, damage boosts, energy refills, and debuff cleansing. If you are building Sunday, here's everything you need to know to maximize his potential!

 

Ability Analysis: Precise single-target, Max Buffs

Skills priority:

Skill = Ultimate = Talent > Basic ATK

Skill:

Effect: Targets 1 ally (+ their Summons). Grants 100% Action Advance (they act immediately!) and DMG Boost for 2 turns.

Key Notes:

The 100% action advance effect is extremely powerful, allowing key allies (and their summons) to immediately take action. Summons will take their turn again right after the ally.
No Action Advance on other Harmony units.

When releasing Skill, removes 1 debuff from a single ally (identical to Bronya's Skill effect).
+20% CRIT Rate at max Trace(for 3 turns) . The CRIT Rate bonus is very impressive (A max-level 5-star CRIT Rate body piece only provides 32% CRIT Rate.)

Ultimate:

Effect: Applies "Energy Halo" to 1 ally (+ their Summons). Lasts until Sunday takes 3 actions (at most 3 turns).

Energy Halo effect: Restores Energy equal to 20% of the target's Max Energy. Boosts CRIT DMG based on Sunday’s own CRIT DMG!

Hidden mechanism: Smooth & Efficient

Sunday has powerful bonus trace effects, making its mechanism more perfect:

• Start battle with +25 Energy → This makes him often have enough energy to immediately release Ult after releasing his Skill at the beginning.
• When using his Skill on a target with Energy Halo, Sunday restores 1 extra Skill Point. This means during Energy Halo’s duration, using his Skill becomes SP-neutral (or even SP-positive) – effectively free action advance!
• Ult’s Energy restore has a minimum of 40 Energy (great for low-Energy DPS like Dan Heng).
• Skill’s +20% CRIT Rate lasts 3 turns (with max Trace).

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Relic Builds: SPD & CRIT DMG Optimizationst

Best Relic Set: Sacerdos’ Relived Ordeal (4-piece)

When Sunday uses a skill, it can further increase teammates' Crit DMG. Additionally, with a two-piece set, Sunday’s speed is boosted, allowing for more frequent skill usage.

Planar Ornament

Lushaka, the Sunken Seas

Enhances Effect Resistance and boosts survivability, perfect for Sunday’s support-debuff hybrid role.

Broken Keel

If Sunday is not enough Effect Resistance should consider Broken Keel, it can increase the Crit Damage and more 30% Effect Resistance by his own.

Main Stats

• Body: Crit Damage%
• Feet: Speed
• Sphere: HP %
• Link Rope: Energy Regen

Sub Stats Priority

• CRIT DMG > SPD > Effect RES > HP%

Mechanical Rationale

CRIT DMG:

• Priority Basis: Directly scales Ultimate's buff strength (1% CRIT DMG ≈ 0.4% teammate bonus)
• Official Kit Synergy: Ultimate: "Hymn of the Blessed" buffs allies based on Sunday's CRIT DMG

SPD:

• Priority Basis: Ensures turn order alignment with DPS (134/143/161 key breakpoints)
• Official Kit Synergy: Skill: "Prayer's Counterpoint" requires SPD tuning for 100% Action Advance efficiency

Effect RES:

• Priority Basis: Mandatory 30% threshold for Broken Keel (Base 18% + 12% substats)
• Official Kit Synergy: Trace: "Purity Feather" grants 18% base Effect RES

HP%:

• Priority Basis: Survival stat (non-core)
• Official Kit Synergy: No direct kit interaction

Optimization Rules

1. CRIT DMG Focus

• Initial Target: ≥180% (post-trace unlock)
• Endgame Target: ≥200%
• *Example: CRIT DMG Body (64.8%) + 5 substat rolls (7.8% each) = 103.8% → Easily achievable*

2. SPD Thresholds

Scenario	Target SPD	Purpose
General Play	134	2 actions in first cycle
Speed Tuning	Less than DPS SPD	Enable "DPS → Sunday → DPS" loop

    
3. Effect RES Requirement

• 30% total activates Broken Keel's 10% team CRIT DMG
• Achieved via: Base 18% + two substat rolls (5.8% each)

4. HP% Positioning

• Only considered after CRIT DMG/SPD/Effect RES targets met
• Low-priority survival buffer

 

Light Cone Recommendations

Best Option (5-star):

A Grounded Ascent: Perfect synergy for amplifying Sunday’s role in applying Remembrance debuffs and dealing damage. If you want to know about more Light Cone's details, you can check Sunday's Kit.

But the Battle Isn't Over (Bronya's LC): Provides Energy Regen, recovers SP after Ult, and a DMG boost. But the DMG boost lasts only 1 turn, and SP recovery has turn restrictions – making it a downgrade from Sunday's signature.

Earthly Escapade (Ruan Mei's LC): Grants team-wide DMG boost (long duration) and restores Energy per wave. Useless Break Effect substat and no SP generation.

 

F2P & Budget Option (4-star):

Past and Future – Enhances ally skill utility while still supporting Sunday’s playstyle.

Carve the Moon – Weave the Clouds: After using Skill, randomly boosts ATK/CRIT Rate/Energy Regen. Free to obtain and straightforward.

Dance! Dance! Dance! – Ultimate advances all allies' actions by 24%. Valuable team-wide Action Advance.

Memories of the Past – Restores Energy when attacking. Consider for early-game or resource-limited builds.

 

Light Cone Priority Summary:

Signature LC > Bronya's LC ≈ Ruan Mei's LC > Carve the Moon, Weave the Clouds >Dance! Dance! Dance! > Memories of the Past.

Avoid These:

• [For Tomorrow's Journey] (Robin's LC): Short buffs + ATK% useless
• [Past and Future] ("Clockie" LC): Restrictive conditional buff
• [Planetary Rendezvous]: Only for Imaginary DPS
• Hanabi/Topaz LCs: Hard-to-maintain passive → becomes stat stick
• New 3.4 BP LCs: Break Effect/DoT focus → No synergy

 

Team Composition

Sunday fits virtually any hypercarry team.

Undying Warrior: Mydei Team

Composition: Mydei + Sunday + Tribbie / Jiaoqiu + Luocha / Gallagher / Hyacine

Core Mechanics:

• Mydei activates ATK buffs by consuming own HP, synergizing with Gallagher’s ATK-based healing to sustain "stronger at low HP" cycles.
• Sunday’s Action Advance and DMG boosts enable Mydei to instantly activate "Godslayer Be God" state.Tribbie’s "Audience Zone" vulnerability and Pela’s DEF shred amplify damage.
• Hyacine Alternative: Replace Gallagher with Hyacine for stronger healing/HP buffs if survival is pressured.

 

V3.4 Phainon Team

Composition: Phainon + Sunday + RMC / Tingyun + Huohuo / Gallagher

Huohuo’s value:

• Skill: Healing + ATK boost
• Ultimate: Team Energy Regen (accelerates "Kindling" stacks)
• Frequent debuff cleanse to prevent interruptions

Gallagher Alternative: Better SP generation for SP-intensive teams.

 

Aglaea High-speed Team

Composition: Aglaea + Sunday + Robin + Huohuo

Synergy Breakdown:

• Sunday: Action Advance (allies + Eidolons), Energy Regen, stat buffs. Signature LC generates SP.
• Robin: Teamwide Action Advance, ATK boosts, and follow-up DMG. SP-negative without Eidolons (similar value to Trailblazer).
• Huohuo: Energy Regen, ATK buffs, and survival sustain.

SPD Tuning:

• Sunday: 134+ SPD
• Aglaea: Ensure SPD ≥ 2× Sunday’s SPD during Ultimate.

 

Eidolons: Core Upgrades

E1:

• Using Skill → Target ignores 12% DEF
• With Summons: DEF ignore → 18%
• Massive DPS spike (like Topaz E1).

E2:

• Start battle: +8 Energy
• Use Ultimate: Recover 2 SP
• Energy Halo target: +30% DMG
• Fixes energy/SP economy + adds permanent DMG boost.

E4:

• Using Skill: +8 Energy
• Minor bonus.

E6:

• CRIT Rate buff: Stacks ×3 (max +60%), lasts 4 turns
• Ultimate also applies 1 stack
• CRIT Rate >100% → Excess converts to CRIT DMG (1%→2%)

 

Final Verdict: Greatness Needs No Explanation

Sunday redefines single-target support as a Harmony path master. He combines:

▲ 100% action advance (summons included!)

▲ Energy restore (20% Max Energy, min 40)

▲ Massive +20% CRIT Rate

▲ CRIT DMG buff scaling with his own stats

▲ Removes 1 debuff from an ally

▲ Starts battle with 25 Energy

▲ SP-positive rotations (refunds SP during Energy Halo)

▲ Technique's +50% nuke DMG

→ All in one buttery-smooth kit.

Build Philosophy:

• SPD-tune (Fast or Slow playstyle)
• Maximize CRIT DMG
• E0 is complete – E1/LC are luxury upgrades

Finally, Sunday is truly one of the strongest assistants in v3.4. As "Bro Sunday", he sets the new gold standard for hyperbuffing. Add him to your roster, and feel your Trailblazing power hit unprecedented heights.

Greatness needs no explanation!

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