How a Sustainless E2 Acheron Team Beats the Elation Boss in HSR 4.6

Running Acheron without a sustain unit sounds like a fast way to lose a run. Against the Elation boss — Harmonious Choir The Great Septimus, seen here in the stage labeled King in Check — a 16-cost lineup of Acheron, Robin, Mortenax Blade and Ashveil does it anyway, by turning nearly every defensive relic slot into raw HP and leaning on buffs and debuffs to keep the damage where it needs to be.

Quick answer: Put HP% orbs and HP% ropes on almost every unit in the team, keep Robin’s Ultimate and the Hemoveret debuff up for the attack buffs, and clear the boss with Acheron Ultimates. Swapping Ashveil for Aventurine Waveflair trades a damage slot for a stream of follow-up attacks that charge Acheron faster.

Note: The footage behind this setup comes from a modded client with custom character names and skins — Aventurine Waveflair, Robin Summeretto, Mortenax Blade and Ashveil all appear with altered appearances. Treat the numbers as a demonstration of how the pieces interact, not as a live-server clear you can reproduce slot for slot.

The sustainless Acheron lineup and the HP relic trade

The first version of the team is Acheron, Robin, Mortenax Blade and Ashveil. There is no healer and no shielder, so survival comes entirely from stat padding. Almost every character runs an HP orb and an HP rope instead of the usual damage main stats, which pushes two of the four units past 7,700 HP and turns the boss’s big hits into something the team can absorb rather than avoid.

Honkai Star Rail battle screen with the Enemy's Turn indicator highlighted as the boss acts — The enemy turn indicator lights up while the team takes hits with no healer on the field. Image: HoYoverse

That trade normally guts a team’s damage. It does not here, because the attack buffs come from elsewhere. The Hemoveret debuff plus Robin’s Ultimate stack enough attack onto the party that Acheron’s Ultimate still lands in the range it needs to, even with orbs and ropes handing out HP instead of attack percentage or elemental damage.

A CRIT Hit lands on the boss as the Battle Metrics panel and Total Damage counter tick upward — A critical hit registers while the battle metrics panel tracks total damage for the run. Image: HoYoverse

How the fight plays out across both halves

The first half opens against the boss’s minions. Acheron’s Ultimate does the heavy lifting and wipes the opening wave almost on its own, with Mortenax Blade and Robin filling in around it.

Robin’s Ultimate goes up before the transition so the buff window overlaps the second half. This is the part that makes the HP-heavy relic spread survivable without costing a clear.

In the second half the team focuses the boss and strips its toughness bar. Once the bar empties, the fight moves into Phase II.

The Phase II banner appears across the boss battle screen after the toughness bar breaks — The Phase II banner marks the transition once the boss’s toughness bar is broken. Image: HoYoverse

Acheron Ultimates carry Phase II from there. One lands shortly after the transition to chunk the health bar, and a second finishes the boss off, ending the run on the Battle Over screen.

What changes when Aventurine Waveflair replaces Ashveil

The second run keeps Acheron, Robin and Mortenax Blade and drops Ashveil for Aventurine Waveflair in a support role. At E1 he fires off follow-up attacks repeatedly, and that volume of extra hits is the whole point — it feeds Acheron’s charges faster than the original fourth slot did, so her Ultimate comes back around sooner.

That pace shows up in the first half of the second run, where Acheron’s Ultimate arrives early and the all-type resistance reduction stacks pile up on screen.

Repeated All-Type RES Reduction notifications stack on the battle screen during Acheron's Ultimate — All-Type RES Reduction effects stack up as Acheron’s Ultimate goes off in the second run. Image: HoYoverse

The boss half follows the same shape as before, but the pressure from the added follow-up attacks pushes it into Phase II sooner. Acheron’s final Ultimate closes it out.

Boss encounter screen showing Phase II and Crimson Knot during the All Are Within Me sequence — The boss enters Phase II, with Crimson Knot flagged on the encounter screen. Image: HoYoverse

It is worth being clear about why this works at all. Aventurine Waveflair is a 5-star Quantum character on the Elation path, and his Talent gives him Fervor and Punchline every time a teammate attacks — once Fervor hits its threshold he fires an Elation Skill on his own. In a team built around frequent attacks, he generates hits constantly, which is exactly the resource an Acheron shell wants.

Level 80 stats behind the run

Every unit is at level 80/80. The defensive main stats are visible in the HP and DEF columns, while Acheron and Ashveil keep the offensive numbers concentrated where they matter.

Character	HP / ATK / DEF	SPD	CRIT Rate / DMG
Aventurine Waveflair	5,017 / 1,446 / 1,503	180.0	93.5% / 176.1%
Robin Summeretto	8,197 / 1,740 / 929	173.0	52.1% / 95.3%
Mortenax Blade	7,738 / 1,340 / 1,152	143.4	75.3% / 147.2%
Ashveil	4,431 / 2,697 / 942	124.2	94.2% / 145.6%
Acheron	4,724 / 3,487 / 1,325	101.0	67.3% / 207.2%

Aventurine Waveflair’s 180 SPD is not cosmetic. His Party of Euphoria trace raises his Elation by 30% once he reaches 160 SPD, then adds another 1% for each point above that, so speed is a damage stat for him as much as a turn-order stat.

What this means for live-server teams

Aventurine • Waveflair is a 5-star Quantum unit on the Elation path, obtained from the Over the Gilded Tides warp with Summer Rides the Surf as his exclusive Light Cone, and his release is dated September 12, 2026. As a main DPS he wants Ever-Glorious Magical Girl relics with the Punklorde Stage Zero ornament, CRIT Rate on the body, SPD on the feet and Energy Regen on the rope.

The takeaway from the Acheron run is simpler than the build sheet, though. Acheron’s ceiling is tied to how often her Ultimate comes back, and a unit that attacks constantly without asking for skill points is a clean way to get there — which is the same logic behind pairing her with two Nihility debuffers and a follow-up sustain on live accounts. The HP relic spread is the part to be careful with: it works against a boss whose damage pattern you already know, and it is a much worse bet anywhere you are still learning the fight.