Every boss. Every region.

Main story bosses, region-by-region.

Bosses by difficulty tier.

Tier ranks reflect difficulty within a blind-run pacing, not raw DPS thresholds. S-tier fights are the ones you remember; C-tier fights are the ones designed to teach a specific mechanic.

Secret bosses (9)

The secret-boss roster has Dugin (Ossex) and Mirren (Coltrane Peak) confirmed. The remaining 7 slots are placeholders pending wiki.gg / Sportskeeda cross-check. None of the secret bosses are required for the campaign — they unlock reward trinkets and contribute to the completion percentage.

What S / A / B / C mean

The tier ranking reflects difficulty within a blind-run pacing — not raw DPS thresholds or absolute reaction-time requirements. A tier ranking is a prediction of how many attempts the average blind first-run player will need to clear the fight cleanly. The four tiers in plain language:

• S — Campaign Peaks.The fights you remember. Multi-phase composites (Thorne's 3-phase chain, Lionel's final 3-phase chain) where each phase runs on a single life pool with no rest between, and death restarts at phase 1. Expect 8-12+ attempts on the final phase even after the earlier phases click.
• A — Hard Reads. Tight projectile / lane reads. Two or three failed attempts before the rhythm clicks. Includes Carving Man (column reading), Mined Mind (diagonal-safe geometry), Locomotress Agnes (fall-off lethality), The Congealed (counter-intuitive inside positioning).
• B — Gate Bosses. First-region gates and mid-campaign milestones. One or two reads to clear after you internalise the telegraph. The Duchess, Hulk Trooper, Madd House, Nox Beast, Major Miner, Icebound Cavern, and Orrery Warden all sit here.
• C — Teaching Bosses. Designed to teach a mechanic. Few players die more than once on these. Includes Nether Kraken (dash mechanic teach), Maxi (dash rhythm drill), Dugin (sub-mechanic teach).

Tiering is opinionated, not data-driven from anonymised telemetry. We tier based on frame-by-frame review of two full-game playthroughs + the Kakuchopurei boss-fight compilation. If you bounced off a fight harder than our tier suggests, your read may differ — that's expected and welcome.

How the campaign escalates

The 17-boss main roster + 9 secret roster scales intentionally across the campaign's three acts:

• Act 1 (Prologue + Ossex + Queensbury Crypt). Teaching bosses + first gate boss. Nether Kraken teaches the dash; Hulk Trooper teaches positional discipline; the Duchess teaches phase inversion. Most blind players clear this act in 5-8 hours of playtime.
• Act 2 (Septemburg, Nox's Bayou, Bone Beach, Coltrane Peak).The any-order + gated rotation. A-tier bosses (Carving Man, Mined Mind, Locomotress Agnes) anchor this act. Each region's mechanic is distinct — projectile spread, toxic puddles, radial geometry, slip floors. Roughly 12-15 hours of playtime.
• Act 3 (Astral Orrery + Lionel). S-tier composite final. The Orrery Warden + The Congealed warmups + the 3-phase Lionel composite. The act is short on minute count but high on difficulty. Speedruns clear Act 3 in 2-3 hours; blind first runs often spend 5+ hours on the Lionel chain alone.

The Thorne composite (S-tier) spans acts 1-3 across his three encounters — phase 1 inside Ossex's Radiant Manor, phase 2 mid-campaign return, phase 3 corrupted wolf-form pre-final. Each phase runs on a separate life pool with story-flag gating between encounters.

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