This is one of the main bosses in the game and is located in the large, open battlefield of Ashina Castle Gate Fortress. You won’t be able to bypass or miss him since you’re required to defeat him before you can proceed to the next area.
How to defeat this boss?
Gyoubu can give you a hard time due to his speed and his weapon’s range. Before facing him, having access to Chasing Slice and Grappling Hook Attack will make this battle bearable. Chasing Slice allows you to perform a dashing slice forward after throwing a shuriken. The Grappling Hook attack will give you a chance to do a powerful attack after using your grappling hook. These two skills belong to the Prosthetic Arts skill tree, which is unlocked by talking to the Sculptor after crafting three prosthetic tools.
During the battle, avoid evading Gyoubu’s attacks too much. In order to get a chance to perform counterattacks, you’ll have to block his normal attacks. As long as your posture is upgraded at least once, you should be able to tank some of his attacks. You can also recover your posture faster as long as your HP is high enough.
His powerful overhead and upward slashes of his spear should be avoided however. A simple side-step should be enough to get away from its massive strike while giving you the opening to land quick counterattacks. Watch out for his perilous, long-range spear thrust as well.
There are several chances to attack him. Watch out when you successfully block his normal attacks, after his horse makes a sharp turn, or after you evade his spear slashes or thrusts. You can conveniently use Chasing Slice to quickly close the distance while also dealing damage with your shuriken throw and follow up slash. Your shuriken throw can also interrupt his attacks or even quickly stun him if you land it at the right time.
His spear can also extend to a very annoying long-ranged whip that he can spin around him. This hits multiple times and can instantly kill you if ever you’re not able to block it or get to a safe distance. Fortunately, you’ll know if he’ll do this is when you see him running away and by seeing a green marker above his head. Use your Grappling Hook to interrupt this special attack and get close to him in an eye-blink. If you learned the Grappling Hook attack, you can also land a powerful attack with the right timing, just before you land after using your grappling hook. A successfully executed Grappling Hook Attack will even stagger him.
You can still hook on him even after he swings his spear’s whip form around him. Block his first swing then quickly use your Grappling Hook. The second swing will render you invulnerable since you’ll be in the grappling hook animation. When he’s near death, consider blocking/parrying his normal attacks often so you can counterattack quickly. Repeat the methods and keep an eye of his attacks described above to win.