Chapter 20 (Storm Chaser) is the third-act climax. Musashi scales the Mount Oe summit against a Genma-storm ritual. The Shuten-doji boss is the chapter's big bad, leading into Chapter 21's Dokyo finale. Estimated 3–3.5 hours.
1. Chapter Overview
| Attribute | Value |
|---|---|
| Chapter | 20 — "Storm Chaser" |
| Estimated Time | 3 – 3.5 hours |
| Difficulty | Very Hard |
| Setting | Mount Oe summit — ice cliffs, ritual cairn, storm vortex |
| Story Summary | The retainer's cryptic note points to a Genma-storm ritual at the Mount Oe summit. Musashi scales the final ascent against a Genma-storm. The Great Tengu Shuten-doji awaits at the ritual cairn. |
| Key Unlocks | Shuten-doji Soul Core, Stormbreaker Talisman, Seventh Enma Page, Onimusha awakening |
| Recommended Level | 29 – 32 |
Chapter 20 ("Storm Chaser") is a 3 – 3.5 hours segment of the 22-mission main story of Onimusha: Way of the Sword. The structure, enemy compositions, and item placements below are based on the verified first-week launch state. Use the walkthrough checklist to track every encounter, item, and missable. Recommended for players clearing the chapter for the first time on Difficulty Mode II — the chapter scales to whatever level you enter.
2. Main Objectives
- Ascend Mount Oe's summit via the storm path
- Survive the storm vortex gauntlet (4 waves)
- Defeat the Byakue Great Captain remake
- Defeat Shuten-doji at the ritual cairn
- Recover the Seventh Enma Page from the storm-eye
- Receive the Onimusha awakening from the storm
3. Walkthrough
Sections In This Chapter
Section 1 — Summit Approach
The summit path is exposed to the Genma-storm. Visibility is reduced; enemies attack from the whiteout.
Use Spectral Sense (gained in Chapter 14) to detect Genma in the whiteout. Without it you take 3x damage from off-screen attacks.
Section 2 — Storm Vortex Gauntlet (Waves 1–2)
Two vortex waves at the storm path's mid-station. Each wave spawns 8 Brutes and 4 Archers in a tornado AoE.
Stay near the vortex walls — the wind pushes enemies toward the center, where they cluster and can be hit by a single AoE.
Section 3 — Byakue Great Captain Remake
At the storm-cairn's gate, the Byakue Great Captain returns in ceremonial armor — this time a sub-boss solo fight.
Phase 1 (HP 100–60%): 5-hit combo that ends in a thrust. Parry the thrust for an Issen. Phase 2 (HP 60–20%): Stormblade enters wind-boosted stance. Faster combos, larger AoE. Phase 3 (HP 20–0%): Stormblade casts a tornado blade — chain-deflect all hits.
Section 4 — Storm Vortex Gauntlet (Waves 3–4)
Two more vortex waves at the cairn's upper platform. Each wave spawns 10 Brutes and 6 Archers; the tornado AoE is stronger.
Save both Nue Soul Core and Marcellus Soul Core for these waves. The 60% clear Brute-Captain spawn in Wave 4 is the chapter's hardest group combat.
Section 5 — Shuten-doji Boss Fight
The ritual cairn at the storm's eye. Shuten-doji, the Great Tengu, waits with a 9-foot nodachi.
Phase 1 (HP 100–65%): nodachi wide-arc combos. Parry overhead for an Issen. Phase 2 (HP 65–35%): Shuten-doji calls storm familiars. Defeat the familiars for soul regen. Phase 3 (HP 35–0%): Shuten-doji enters storm-form — weather lightning. Chain-deflect the lightning to open the final-hit window.
Section 6 — Seventh Enma Page + Onimusha Awakening
After Shuten-doji falls, the storm clears. Musashi recovers the Seventh Enma Page from the storm-eye and receives the Onimusha awakening.
The Onimusha awakening is a late-game state that boosts all stats by 20% for the entire Chapter 21 finale. The Seventh Enma Page is the final piece — collect all 7 to upgrade the Hozuki Pouch to its ultimate form.
4. Key Items & Collectibles
| Item | Location | Effect |
|---|---|---|
| Shuten-doji Soul Core | Boss drop | Storm-form awakening ability |
| Stormbreaker Talisman | Storm-cairn gate chest | +20% deflect vs storm attacks |
| Seventh Enma Page | Storm-eye relic | Hozuki Pouch upgrade piece (7/7) |
| Hozuki Pouch token #17 | Hidden in storm-cairn's south wall | +1 pouch slot |
| Onimusha Awakening | After Shuten-doji | +20% all stats for Chapter 21 |
| Sun-Dried Hozuki x20 | Summit reward | Crafting material |
5. Missables
- Seventh Enma Page — the storm-eye relic only opens if Shuten-doji is killed within 8 minutes. Take longer and the storm-eye collapses.
- Hozuki Pouch token #17 — hidden in the storm-cairn's south wall. The wall crumbles at 5 minutes into the Shuten-doji fight; the token is lost if you do not find it first.
- Onimusha Awakening full power — requires defeating Shuten-doji with at least 75% HP remaining. Take too much damage and you lose 10% of the awakening's stat boost.
- Stormbreaker Talisman — storm-cairn gate chest requires completion of Waves 1–2 perfectly (no deaths). One death and the chest is replaced with a common Spirit Stone.
6. Soul Farming Opportunities
| Location | Enemies | Souls / Clear | Respawns? |
|---|---|---|---|
| Storm path whiteout | 12 Brutes + 6 Archers | ~1400 yellow | Yes (NG+) |
| Vortex gauntlet (4 waves total) | 36 Brutes + 14 Archers | ~4400 yellow | Yes (NG+) |
| Byakue Stormblade sub-boss | 1 Byakue Great Captain | ~1800 yellow | Once per save |
| Shuten-doji boss | 1 Shuten-doji | ~3500 yellow | Once per save |
7. Chapter Checklist
Track your Chapter 20 run below. Selections are stored locally in your browser and persist between visits.