Sephiria Library Boss – Erma and Pantaxis Guide

Overview

The Sephiria library boss refers to the two main boss encounters in the third stage of Sephiria, the Library. These are Erma, the Crazy Scientist, and Pantaxis, the Guardian of the Library. Erma is the standard boss that appears from Chapter 1, while Pantaxis is an alternate boss added in Chapter 2 that replaces Erma with a certain probability. Both bosses share the same stage defense value of 46, which reduces incoming damage by approximately 34.06% (or 38.02% with two pieces of protective armor active).

The Library stage is a significant difficulty spike in the game. Both bosses require mastery of dashing, parrying, and pattern recognition. Player reports describe the Library as the point where the game begins demanding consistent defensive play rather than aggressive trading.

Data Table

Erma's Phase Breakdown

How to Obtain (Encounter Conditions)

Erma, the Crazy Scientist

• Appears at the boss battle node at the end of Stage 3 (Library) from Chapter 1 onward.
• The fight is a three-phase encounter. You first fight the golem that Erma pilots. The golem has separate hitboxes for its head and both hands, so wide-area attacks can hit multiple parts simultaneously.
• When the golem's health is depleted, Erma pops out and must be defeated to advance to the next phase.
• Special interaction: On your first visit to the Library in Chapter 1, Erma may appear on the field outside the boss arena. If you attack her during this encounter, she puts up a shield and disappears. However, if you use crowd control (such as stun) before her shield activates, you can kill her and skip the golem fight entirely. This skip grants no rewards, and you will have to watch the Erma encounter event again on your next run.

Pantaxis, the Guardian of the Library

• Appears at the boss battle node at the end of Stage 3 (Library) from Chapter 2 onward.
• Replaces Erma with a certain probability (player-reported as random chance).
• Unlike Erma, Pantaxis is a single-phase boss with no phase transitions.

Uses

Why Fight the Library Bosses

Defeating either library boss provides standard boss rewards:

• A set amount of sapphires (always dropped)
• Artifact rewards
• Slate rewards
• Additional dice drops depending on your fate imprint status

These rewards are essential for building character power heading into Stage 4 (Wasteland). The artifact and slate rewards can significantly shape your build for the remainder of the run.

Erma as a Dodge-Synergy Target

Player experience from a community build video highlights Erma as an excellent boss for activating dodge-based synergies. Erma's attack patterns are numerous and well-telegraphed, making her a reliable source of dodge triggers. The build in question used the Green Robe item (which activates a strike on dodge) combined with Lerid's Battle Bracelet and rubber band to restore dash charges on successful dodges. This allowed nearly infinite dashes during the Erma fight, turning her many attack patterns into a source of damage output.

Pantaxis Strengths and Weaknesses

Community player reports indicate Pantaxis is a divisive boss:

• Strong against: Players who rely on sword-and-shield blocking. The sphere-charge attack cannot be blocked unless the angle is correct.
• Weak against: Freeze and stun debuffs. These can interrupt Pantaxis's patterns, potentially skipping the annoying charging attack.
• Note: The invincibility pattern (where Pantaxis leaves the map) may not have an internal cooldown, so it can be used repeatedly, forcing a bullet-hell-style fight.

Upgrades and Changes

Battle Stance Modifier

If the Battle Stance option is active, all boss gimmicks and attack patterns are strengthened. For Erma specifically, this adds a black shockwave variant to her ground-punch attack. This black shockwave tracks the player differently than the standard yellow one, so dashing timing must be adjusted.

Erma's Status Ailment Interactions

• Status ailments applied to any one of Erma's three parts (head, left hand, right hand) are applied to all parts.
• Freeze: If the hands freeze, the head also freezes.
• Burn: Deals triple damage.

Chapter 4 Changes

From Chapter 4-2, the Stage 1 boss pool changes, but the Library bosses themselves remain unchanged. However, the overall game difficulty curve shifts, and player reports suggest that by Chapter 4, you should rely more on normal attacks and soul-based sub-weapons during the Library rather than forcing dodge-based builds, as the risk-reward becomes less favorable.

Related Pages

• Sephiria Second Boss – Covers the Stage 2 boss encounters.
• Sephiria Bosses – Complete index of all boss encounters in the game.
• Sephiria Dragon – Information on dragon-related content.
• Sephiria Kalim's Form – Details on Kalim's transformations.

Version Context

The information on this page reflects the game state as of July 31, 2026. Key version notes:

• Chapter 1: Erma is the only Library boss.
• Chapter 2: Pantaxis is added as an alternate boss with a random chance to replace Erma.
• Chapter 4: The Remnants of Haj replaces the Stage 1 bosses from Chapter 4-2 onward. The Library bosses are not directly affected by this change, but player builds may shift due to the increased difficulty of Stage 1.

Sources

The following sources were used to compile this page:

• Sephiria/Boss – Namu Wiki
• Sephiria Infinite Dash Build – YouTube (community player experience)

Unverified information: The exact probability of Pantaxis replacing Erma is not publicly documented. The specific reward quantities (sapphire amounts, artifact values) are not listed in the available source material.