How to Unlock Onimusha: Way of the Sword’s Secret Boss (Byakue) | Demo’s Special Challenge

Onimusha: Way of the Sword’s demo hides a secret boss fight. Land 10 Issen kills and finish the demo, and a new option shows up on the main menu: Special Challenge. This is a fight against Byakue, an axe-wielding monster on a difficulty setting that doesn’t exist anywhere else in the demo. Keep reading to learn how to unlock the boss fight and how to actually beat it.
Spoiler Alert: This guide was written for the demo version and may change with the full release. Check again later.
What You’ll Read:
How to Unlock the Onimusha Secret Boss
You need 10 Issen kills anywhere in the demo, then finish it. That’s the whole condition. A counter on the left side of the screen tracks your Issen total, with Kanji next to it that turns gold once you reach 10. The good news is that you don’t lose your Issen count if you die.

Once you’ve got your 10 and finished the demo, “Special Challenge” shows up as a new option on the main menu. Pick it, and you’re dropped straight into Byakue’s fight, on a difficulty the rest of the demo doesn’t come near.

Fastest Way to Farm 10 Issen
Issen counts even if you kill the same enemy twice. Fight a group, die on purpose, then go finish them off with Issen again. Repeat until the counter turns gold.
Don’t want to throw runs away on purpose? Load a save from right before the Oni fight and farm your 10 there instead. Either way gets you there.

Who Is Byakue
Byakue is known as “Hundred Defilements,” and it looks the part. This boss is a rock-hard, white-furred thing that’s part gorilla, part bear. It fights with a massive axe, and yeah, that surprises people who only saw silhouettes in early footage and assumed it was just a charging brawler.
It’s got a grab attack that uses its own hair, and here’s the part that changes how you fight it: the longer the battle drags on, the more blood it gets soaked in, and the stronger it gets. Standing around trading hits and hoping to outlast it is the wrong strategy. This thing rewards speed, not patience.
How to Beat Byakue Boss Fight
Your instinct will be to keep moving and dodge everything. Don’t. Standing your ground actually puts you in the right spot when Byakue charges, so you can just side-step it instead of scrambling out of the way. That opens it up for a hit in slow motion.
From there it’s the standard boss loop: strike and counter to decrease the red stamina bar, then cash it in for a Break Issen once it’s empty. Break Issen lets you pick which body part to hit, so go for whatever’s exposed.
Byakue only gets tougher the longer it bleeds. So land big hits when you get an opening instead of poking at it. Expect more than one attempt; most players needed several to learn the loop.

Is Byakue in the Full Game Too
Yes. Byakue isn’t some demo bonus. It’s a real boss you’ll hit in Kyoto, well after the demo ends and after you take down Rasho-gan at Yasui Konpiragu Shrine.
The story is that Kyoto’s choked by toxic fog coming from a cluster of eerie plants, and Byakue shows up to stop you from cutting down the last one. Clear it and the fog lifts, more of Kyoto opens up, and townsfolk start filling the streets again. This isn’t optional either. It’s a part of the main story.
That’s everything you need to know about the Onimusha secret boss. Was it difficult for you, or did you cheese it? Write to me in the comments below.
One last thing: have you wondered who the voices are behind these characters? That’s what I thought! Learn about them in this Onimusha voice actors list.


