Musashi's katana is your backbone in Onimusha: Way of the Sword, but the six Oni Armaments are what give you real flexibility against the Genma. Summoned through the Oni Gauntlet using Blue Souls, these supernatural weapons cover everything from crowd control and healing to raw burst damage and stance-breaking. Four of them you'll pick up naturally through story progression. Two require a small detour, and skipping them will cost you in the late game.
What are Oni Armaments and how do they work?
Oni Armaments are supernatural weapons tied to the Oni Gauntlet. You fuel them with Blue Souls, which drop from defeated Genma, from landing hits during the Blazing State, or from hitting a boss's purple weakspots with a Break Issen. Each armament draws from the same Oni Power gauge, so you're always choosing between them rather than spamming all six freely.
Every armament can be upgraded using Oni Stones and red souls, which unlock improvements that meaningfully change how useful each weapon is in tougher encounters. Don't neglect upgrades, especially for the ones you use most.
All Oni Armament locations at a glance
Two Celestials
These twin daggers are the first armament you'll receive, and the game puts them directly in your path. During The Stage is Set at Kiyomizu mission, you'll follow spider threads into a cave. After killing the spider weaving the second thread, open the chest it was wrapped around to claim the Two Celestials.
The Two Celestials' defining trait is Yellow Soul generation. Absorbing Yellow Souls restores health, which makes this armament the go-to for tough boss fights where you're taking more damage than you'd like. The damage output is decent too, capable of outright killing weaker Genma. Across all six armaments, this one arguably has the highest floor because healing is always useful.
two celestials map location
Wind Whipper
You receive the Wind Whipper from Ono Takamura during The Oni's Apprentice quest, after unlocking the Deflect skill and completing a drill at the Practice Grounds. This naginata is impossible to miss as long as you complete that training sequence.
Musashi spins the Wind Whipper around himself, generating a whirlwind that staggers groups of enemies and blocks incoming projectiles during the spin. The real payoff comes from fire: any nearby open flame, whether a standing torch, exploding barrel, or flaming arrow, will ignite the whirlwind and dramatically increase its damage while setting enemies on fire. The Firebird Flute's projectiles can also trigger this effect if you have enough Oni Power to chain both armaments together.
wind whiper location
Earth-Shakers
The Earth-Shakers are found during What Lurks in the Shadows in the Underground Laboratory. After Dokyo traps Musashi in a room with a ceiling blade, shoot the four spools of thread powering the fans to escape. The chest containing the Earth-Shakers sits just beyond the wreckage.
These twin clubs skip health damage entirely. Their job is depleting enemy stamina, which opens opponents up for Break Issen attacks. They hit a wide area and are particularly effective against armored enemies and bosses. The main drawback is their slow wind-up: you need to anticipate enemy movement before committing to an attack, because a mistimed swing against an enemy mid-power-up animation will waste all your Blue Souls with nothing to show for it. Use them when an enemy is actively blocking, not when they're moving.
For a deeper look at how Break Issen fits into the full combat system, the Onimusha: Way of the Sword combat guide covers every mechanic in detail.
earth-shakers location
Firebird Flute
The Firebird Flute is the most unusual armament in the set. Found in a chest south of the Gojo Street East Spirit Mirror in Eastern Kyoto during the Roots of All Evil quest (also referenced as the Shadows Fall mission), it can be retrieved at any time if you pass it during the quest.
Unlike the other armaments, the Flute doesn't deliver a single burst attack. Activating it lets you launch up to three fireballs by pressing the Oni Armament button again. Each fireball ignites the target and staggers them backward, making it an excellent combo extender. The catch is that you must keep the Firebird Flute equipped to fire the projectiles you've generated. Swap to another armament mid-sequence and you lose the shots.
firebird flute map location
Flashing Void
This lightning-imbued spear is the only armament designed purely to deal damage. You'll find it in a cave chest on the Mount Oe map during The Demon on the Mount mission. Head to the Castle Entrance Spirit Mirror and follow the cave along the main path. It's slightly off the beaten track, which is why it qualifies as missable.
Flashing Void removes large chunks of enemy health in a single hit and can one-shot most standard Genma, including the Hitotsume Sho swordsmen that cause problems throughout the mid-game. Killing enemies with Flashing Void awards bonus red souls, and with the right upgrades purchased, it can execute stance-broken enemies outright. Save it for priority targets and elites rather than wasting it on basic enemies.
flashing void map location
Still Water
Still Water is the most easily missed armament in the game. It's located in a chest deep in a tunnel near the Swamp 1 Spirit Mirror in the Arashiyama map's Swamp area, sitting by a shrine well off the main path.
Activating Still Water infuses Musashi's sword with power and causes each hit to generate purple souls, which build the Oni Awakening meter. When the buff is about to expire, pressing the Oni Armament button again releases a golden wave of sword energy that deals solid damage and generates even more purple souls. The timing matters: trigger the energy release at the last second of the buff to maximize soul generation before it ends. This armament rewards players who prefer staying in melee rather than relying on armament burst windows.
still water map location
Which Oni Armament should you prioritize?
For most of the game, the Two Celestials carry the most consistent value because healing is always relevant. The Earth-Shakers become essential once bosses start resisting your basic attacks, and Flashing Void handles any elite Genma that would otherwise eat too much of your resources. Still Water is the best late-game option if you want to keep pressure on through basic attacks rather than armament windows.
The Wind Whipper and Firebird Flute are situational but genuinely powerful in the right rooms. Don't sleep on the fire synergy between them.
For everything else you need to get started, the full Onimusha: Way of the Sword strategy guides collection has you covered from system requirements to boss strategies.