Arcane Lineage How to Beat Metrom's Vessel

Metrom’s Vessel is the endgame named fight players search after Handaconda stops feeling like the final exam. Community writeups place the encounter in the Temporal Jailhouse and treat it as a coordination check, not a solo timing flex. This page is the practical clear sheet. Confirm summon items, exact HP thresholds, and drop names on Discord and Trello the week you run it — raid math moves.

You should already own a Super Class, a working party, and a Trial stack you can survive. If you are still on the Caldera slime loop, read getting started and the early boss guide first.

How the fight is structured

Public guides describe two broad phases:

Phase 1 — establish control. Bring the boss down with clean QTEs, Daze uptime, and assigned interrupt or Guard calls. Do not dump your entire burst kit before the party proves it can live through the opener.

Phase 2 — pink wings. Community notes flag a dramatic damage reduction and reflected damage once the Vessel shows pink wings at low HP. Greedy multi-hits that ignored the reflect warning are how “full DPS” parties wipe themselves. Swap to planned burst windows, shields, and controlled hits.

Some writeups also call out a recurring true-damage pressure spike on a timer or turn count. Treat that as a heal-and-cleanse assignment, not as a DPS race. If your healer is dead, the spike does not care about your Assassin’s poison stacks.

New Metrom's Vessel guide for Arcane Lineage

Party roles that actually clear

Seat	Job
Sustain	Saint / Paladin / Lionheart-style sponge — keep the party standing through reflect and true damage
Primary DPS	Assassin poison or another DoT seat that does not panic-swap into reflect
Setup	Sunder / Vulnerable / alchemist pressure so the HP bar moves without needing suicidal greed
Flex	Second DPS or cleanse depending on the week’s mechanic card

A five-Assassin meme can work on a patch where reflect is weak. It is not the default plan. Read the Assassin build if that is your seat, then bring friends who Guard.

Entry and preparation checklist

1. Confirm the live summon requirement (Void Key style entry items appear in community notes — verify before you vendor the wrong key).
2. Identify Grove gear. Crit and sustain rolls matter more here than fashion.
3. Set Trials you can survive. Mortal Greater on a first Vessel learn is how people delete a week of progress for a multiplier screenshot.
4. Assign who calls the reflect swap. One voice. Not five.
5. Bring consumables for the anti-heal or long stun weeks. Assassin cannot potion the whole raid alone.

Loot and why you are here

Players farm Vessel for late materials and prestige drops community notes summarize as Soul Dust style rewards and other high-tier craft inputs. Exact percentages belong on Trello, not in a frozen paragraph. If you only need Handaconda’s Gynx route, stay on the Handaconda guide. Vessel is the next homework, not a replacement for Grove Corruption.

Common wipe reasons

• Ignoring pink-wing reflect and “finishing” the boss with unprotected multi-hits.
• No assigned healer because everyone queued as DPS from a tier-list short.
• Learning the fight on a one-life Greater Trial.
• Bringing a pre-Horizons Hard-mode checklist instead of a modern Trials plan.
• Treating a YouTube short as a substitute for a callout.

Related reading

Vessel sits at the end of a chain: combat → party → Handaconda → here. Systems under the fight are New Horizons and the live Withered Grove wrapper. There is still no code that skips the Jailhouse.