BEAST/REINCARNATION GUIDE
Language▼

Home / Erymanth Boss Guide

Boss guide · Chapter 12

Erymanth: The Last New Boss Before the End

Erymanth is the only boss on the entire roster recorded as weak to Explosive, and the last unfamiliar Nushi the campaign introduces — everything after it is either a rematch or the finale. It appears once, at Level 47, in the chapter before the ending. Here is what our launch coverage establishes about the fight, its unusual weakness, the ammunition question it raises, and the arts it closes out.

Compiled from this site's own launch guides · Last reviewed September 11, 2026

One encounter, in Chapter 12

Our boss list records Erymanth once, in Chapter 12 — the chapter titled The Firmament — with the boss at Level 47. No rematch, no earlier appearance.

It shares that chapter with the Kunai & Kirin resolution at Level 49, and our walkthrough lists both together in its final stretch, Chapters 11 through 13 plus the epilogue, alongside the last Shidou & Nue encounter in Chapter 11 at Level 48 and the Beast of Reincarnation itself in Chapter 13. Reading the recorded levels in order, Erymanth at 47 is the first of the two Chapter 12 fights and the lower-level of the pair — and, because every remaining encounter is a return visit or the finale, it is the last genuinely new boss the campaign has to offer.

The only Explosive weakness on the roster

Eleven story bosses, and exactly one of them carries the Explosive label — this one. Our review independently lists Erymanth's weakness as Explosive in its roster summary, so the pairing is recorded twice on this site. The boss list and the walkthrough both give the same one-line tactic: explosive ammunition is the fast route through it.

That raises a question our coverage does not fully answer. The weapons page confirms three enchantable elements in the shipped build — Fire, Lightning and Wet — and describes Fire as igniting the target and being able to trigger explosions. It is tempting to read that as the mechanism behind explosive ammunition; we are not going to. No page here states that Fire and Explosive are the same thing, or that an explosive property is applied through an element slot rather than through a distinct ammunition type. Treat the connection as not confirmed and check what your own ammunition list offers.

There is one supporting hint about ammunition variety being a real system rather than a fiction: our achievement tracker lists an achievement called Manual Maniac whose published condition is obtaining the manuals for every arrow and bolt type, held by 12.9% of owners on its September 7 read (12.5% on the trophy page's August 31 read). Distinct arrow and bolt types with their own manuals plainly exist. Which of them is explosive, our pages do not say.

The Kiku line

The boss list's reward column gives Erymanth Kiku: Bloom Strike II and Finisher: Kiku. As with Ursa's Asagao rewards, the numeral tells you this is an upgrade to an art you are assumed to already own — and as with Asagao, no page on this site records where the first rank of Kiku: Bloom Strike comes from. That origin is not confirmed here.

No Nushi Skill is attached to this fight. That is consistent rather than surprising: our Koo guide documents the Nushi Skill unlock order as ending with Acid Burst Nobudou from Corvus in Chapter 7, with the late-game seals contributing art upgrades and Finishers instead. Our glossary keeps the vocabulary straight: a Nushi Skill is the ability absorbed from sealing a region's apex Malefact, while Blade Arts and Finishers are separate categories of boss-fight unlock.

Practically, a Finisher earned at Level 47 has one chapter of campaign left to be useful in. Our endings guide notes that full completion requires a New Game Plus run, so the honest framing is that Erymanth's rewards are as much NG+ equipment as they are endgame equipment.

Loadout notes

  • Check your arrow and bolt manuals before the chapter. Ammunition types are a documented collectible track, and this is the one fight on the roster whose recorded counter lives there rather than in the three confirmed elements.
  • Stones that reward weakness-matching. The Spirit Stones guide lists Sharpshooter (a 20% to 30% chance to return 1 FP when a ranged weapon exploits an elemental weakness) and Entanglement Increase (3% to 7% to restore the Entanglement Gauge and FP on any weakness-exploit). Both are worth slotting for a fight you intend to win with the right ammunition.
  • Critical and finisher stones suit a Finisher-heavy build. The same guide lists Critical Damage Increase (5% to 25% over five levels) and Final Breath, which recovers 10% to 25% of Emma's health on an execution.
  • Expect balance drift. Our patch notes record that version 1.0.11 on September 8 adjusted Blade Arts, Finishers, Nushi-derived skills and ranged weapons, and changed attack patterns and frequency on certain Nushi. Which bosses were touched is not itemised, so if a pattern here does not match older advice, the patch is a plausible reason.

Completion data

Erymanth's End sits at 24.4% of Steam owners on our trophy page's August 31 read and 25.7% on the achievement tracker's September 7 refresh. Both numbers place it inside the late-game cluster that page describes, where the last four boss achievements sit between 24% and 25% just above the final-boss achievement.

The gap between sealing Erymanth and finishing the game is a few tenths of a percentage point on either read. By this stage the fights are not what removes players; almost everyone who gets here goes on to the ending.

What this page does not claim

Nothing on this site describes Erymanth's attacks, phases, arena or appearance, and nothing establishes how an explosive property is equipped or where Kiku: Bloom Strike I originates. Those four gaps are real and we have flagged each of them in place rather than papering over them with plausible-sounding filler.

Erymanth FAQ

Where is Erymanth?

Chapter 12, titled The Firmament, as a single encounter with the boss listed at Level 47. It shares the chapter with the Kunai & Kirin resolution at Level 49.

What is Erymanth weak to?

Explosive — the only boss on the roster with that label, recorded on both our boss list and our review. Our boss list and walkthrough both recommend explosive ammunition.

Is Explosive the same as Fire?

Not confirmed. The weapons page says Fire can trigger explosions, but no page here equates the two or explains how an explosive property is applied.

What does Erymanth unlock?

Kiku: Bloom Strike II and Finisher: Kiku. No Nushi Skill — the documented Nushi Skill list ends with Corvus in Chapter 7.

Sources on this site

Every figure above is drawn from the following pages of this guide, each of which names the outside material it was checked against:

Last reviewed: September 11, 2026 · Game version checked: 1.0.11 · Every figure on this page is sourced from the pages listed above; where they disagree or fall silent, this page says so instead of choosing.