By - dean9r
Try dodging his rush attacks. But seriously, the easiest way to fight him is to be patient. When he starts rushing between the walls, don't engage, at most use a ranged weapon (if you have speed up) or throw some kunai/shurikens. He's weak to poison.
You can cut his horns during all rush attack (except grab after combo in Dark Realm) which will stagger and stop attack animation. Firestop talisman also help a lot.
I've farmed the hell out of this boss so here are the things I recommend:
Use either Tonfa, Kusarigama, or Splitstaff. The focus here is NOT DPS but Ki Damage
Make sure to put in your shortcut at least 2 Purification Talismans, apply one to your weapon before even entering the arena.
The primary focus is to apply the purification effect on him early on and start draining his stamina. Tonfa has a spinning sweeping kick active skill that works great for this. Kusarigama in high stance is great for damage, ki damage, and applying the status effect but you have to be careful and watch your own Ki because it will go down quickly too. Splitstaff in mid-stance is great also if you are afraid to be too aggressive.
Use Brute Guardian spirits. Katsuie's parryable moves are very high risk-high reward. If you screw up the timing as phantom, or screw up the angle as feral, you will either die immediately or be on fire with little to no ki. Brute is an easy cop out. You will take some damage when parrying but you will also have a much easier time actually getting the parries off.
I HIGHLY recommend you use the Enki Soul Core if it is not already in your kit. This one is super useful for doing ki damage.
The main strategy revolves around applying the purity debuff, and then just ki draining nonstop until you can grapple or force him out of the dark realm. When he shifts between the regular and dark realms you will need to re-apply the debuff as he will cleanse it. When he transitions to dark realm, start wailing on him and then as your combo ends finish with an Enki attack as this will do big amounts of ki damage and, if you do it properly, you will regain ki as you perform the enki soul core move. Be careful with this though, as the vertical movement of the Enki soul core won't be enough to avoid some of his attacks so I recommend only doing this with full or near full health in case he whips out something nasty.
If you are still having trouble, using the following might be useful too:
Firestop Talisman, Steel Talisman, Rejuvenation Talisman, Power Pill, Poison Shuriken, Galnut Broth, and Sacred Water
Thanks man, I switched to use the Enki soul core and it did a lot to his ki. Breaking his horns also helped me when he charged.
There are lots of good tips here, but I think the most important thing to remember in your case is that you can block his rushing attacks. That was a game changer for me.
One simple trick that was the key for me to beat him for the first time: Have some poison shurikens with you. Use it when he tries to grab you, dodge, and throw the shuriken in his back, only ONE shuriken will poison him if you hit his back, and two if you hit his face.
If you poison at every time he enters and exits the dark realm the fight time will be reduced a lot. The poison took about 25% of his health when I beat him, and that's A LOT for such a simple trick.
This is my advice as well. Poison damage will kill this guy faster than anything. And it's practically free.
Sloth Talismans if you have those unlocked. They slow him down so you can dodge his rush easier.
One tip that helped me with him was to dodge through his rush - that is toward him mostly but slightly to the side. If you dodge too far away from him, he will just continue the rush after hitting a wall. If he senses a near miss, he will stop the rush.
Sword user here,Iai or new sword dance his tusks as he charges will stagger him, probably similar with any well timed attack, as other said a lot of dodging
Thanks for all the tips guys, I finally managed to beat him myself after countless deaths, breaking his horns when he charged was very useful.