Shared from PS4. Arc System Works did not pull punches. Stage 9 Boss Nagoriyuki is one of the most infuriatingly difficult bosses in all of Guilty Gear, even moreso than I-No or Justice imo. No wonder the lower difficulties give you a partner...
To unlock this fight, you must defeat Nagoriyuki in stage 8 of the Extreme difficulty path without losing a round. Losing a match does not matter, but the match you defeat him in must be a straight victory.
Nagoriyuki here in stage 9 has all of his buffs from stage 8, which means he deals more damage, he has much greater defense (I believe it's triple), and no restrictions when he enters blood rage, meaning he can still use special moves and block, without losing health. He also has invulnerability on several attacks, including the blood rage activation. In stage 9 he's permanently in blood rage, with your only savior being that dealing damage to him lowers the gauge, and he's briefly stunned when the gauge empties. As a note, his AI behavior also changes to be a bit more cautious when he's at low health, which means you might not be able to get him into the patterns you want. And of course, being that you're required to do the max difficulty route to even get to this fight, his AI is very smart. If your pressure isn't airtight, there's a good chance he can reversal out of it, and you can't play oki against this man at all.
The biggest way to deal damage to him is to try to wall break him, as the wall breaks still do normal damage to him. Even with that, this man still inhales damage.
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