Oninoshima Boss Fights Guide: Attack Patterns, Weaknesses & Best Loadouts

The Wandering Ronin – Kage no Kenja

This guy's a straight-up samurai ghost with a phase-shift dash that'll mess you up if you blink. He spawns near the Great Bamboo Shrine, and honestly, his first phase is just him spamming a three-hit combo with that cursed katana. I found that the key is to bait his dash—he always lunges forward after a heavy overhead slam. Shoot him mid-dash with an SMG to stagger him. Best loadout here is a Twin Mag SMG or a Suppressed Pistol for quick bursts; ARs are too slow.

He drops the Ronin's Wraith Blade (a mythic katana that lets you slash through walls) and a Shadow Vial (two free escapes for third-party situations). That blade shreds structures in endgame circles.

I died 5 times before I figured out that his second phase creates three shadow clones that all attack simultaneously. Don't panic-build. Just sprint diagonally away and pick them off one by one—they have 50 HP each.

The Oni of the Rising Sun – Akuma no Taiyō

This boss is a fire demon that hovers above the Cherry Blossom Fortress. He rains down flaming orbs and does a ground-pounding AOE that ignites everything in a 10-meter radius. The biggest mistake is trying to heal inside his fire zone.

I found that a Kinetic Blade (for mobility) paired with a Heavy Sniper is your best bet. The sniper cracks his glowing chest weak point for 150 damage per shot during his charge animation. He drops the Taiyō's Inferno (a mythic shotgun that leaves a fire trail on the ground) and Phoenix Feathers (a consumable that revives you once with full shield).

I died 5 times before I figured out that you can shoot the red lanterns hanging from the fortress ceiling to drop them on him. Each lantern stuns him for 4 seconds and deals 100 damage.

The Tengu Stormcaller – Arashi no Tengu

This one hovers above Tengu's Peak and summons wind gusts that push you off the mountain. Annoying as hell if you're not prepared. His main attack is a wind slash projectile that curves mid-air—don't try to outrun it, build a wall instead.

Best counter is the Holo Twister AR for sustained damage during his float phase, and a Gatekeeper Shotgun for when he dives down to melee. He drops the Tengu's Gale Fan (a mythic item that launches you and your squad 50 meters in any direction—basically a reusable launch pad with no fall damage) and Storm Brew (temporary immunity to wind effects).

I died 5 times before I figured out that you need to destroy the four wind totems around the peak before he becomes vulnerable. He takes 90% less damage while any totem is active. Take them out clockwise starting from the north totem—it's the most exposed and easiest to hit.

The Serpent Empress – Hebi no Megami

Spawns in the underground cavern beneath Rumble Ruins. She's the hardest boss on the map, no contest. She has a poison spit attack that creates damaging pools on the ground, a tail sweep that breaks structures in a 180-degree arc, and at 50% HP she summons snake minions.

Loadout recommendation: Frenzy Auto Shotgun for the minion waves, Reaper Sniper Rifle for headshots during her stationary spit animation, and at least 6 minis. She drops the Serpent's Fang (mythic SMG with poison rounds that deal 3 damage per tick for 5 seconds) and the Empress Medallion (marks all nearby enemies through walls for 8 seconds after a kill).

I died 5 times before I figured out that standing on the raised stone platforms in the cavern prevents the poison pools from reaching you. The floor is lava, basically. Stay elevated and rotate platforms after each tail sweep.