What a good fucking fight.
Okubo is in a unique position among fighters in that he isn't in a unique position, really, and I think it's really interesting to observe and break down.
One of Kengan Ashura's running themes is that having one fancy trick, even when that trick borders on literal magic, isn't enough to carry you at the peak of combat. You need fundamentals. You need extreme physical fitness. Wakatsuki is a freak of nature, but he's also a good fighter on a technical level. Kaneda's Foresight is a genuinely incredible skill, but he simply doesn't have the physical frame to endure the punishment it takes to activate it in time, or the physical ability to act on his predictions once he does.
But by the same token... People with total commitment, years of practice and experience, and physical fitness are many. You need some kind of edge. Kure Raian (yes, we all rag on him, but the manga means for him to be a contender) has all the Kure training but he also has 100% Removal, which is just fucking magic. Kuroki Gensai is the ultimate Old Master archetype, but he also has the Devil Lance, which is quite literally an 'edge'; the human body doesn't work that way. Wakatsuki has good technique, but he is first and foremost a superhuman freak of nature. Gaolang doesn't have a 'magic trick,' but there is a lot of emphasis put on how fighting without gloves is essentially taking the power limiters off his striking power to allow him, specifically, incredibly fast, incredibly powerful punches as his trademark technique (but more on Gaolong in a moment).
Okubo doesn't really have that. He is one of the best fighters in the world, but he doesn't have the physical edge against Agito, that much is clear from the first cleaver-shaped kick hitting his thigh. And he doesn't have an Advance or a Devil Lance or anything like that. All he has is pure technique, move to move to move, just the dirty business of actually blocking and actually dodging and actually hitting the other guy in the face and actually getting him in a grapple and doing that until the other breaks... And the Fang also has better technique. He doesn't have the advantage anywhere, really.
But the thing everyone finds out after Agito declares that he's downloaded Okubo's moveset and Okubo won't touch him again, Metsudo goes "he's finally stopped playing with his food!" and Wakatsuki writes Okubo's eulogy from the stands, is that there is a level of strength at which you cannot be ignored. It takes an incredible arrogance to look at one of the world's greatest fighters and say, "Now that I have studied all his moves and know my stats are better, he will simply never hit me again." Wrong, idiot! Get punched in the face.
And this ties into the one thing Gaolang and Okubo have in common, alone among all the other Kengan fighters (Sekibayashi being an odd exception in the middle, as pro wrestling is kind of its own thing): They're public fighters. Which means they can't have a 'hidden edge.' That's the open secret everyone tacitly agrees not to talk about in this series (except Kaneda and Chiba, for whom this is their only hope at victory): any surprise advantage or unique quirk these two have would be instantly publicized and analyzed and dissected the moment they used it in a match. The highest tier of Kengan matches are private, and if your best fighter loses to Kiryu's Rakshasa's Palm, you aren't going to go public with it, you're going to keep the knowledge of the Palm to you until you've found a counter to it because knowing its existence is the only unique advantage you have against Kiryu compared to everyone else. Nor does seeing the Palm, or Rei's Lightning Flash or any of these moves, once in a single fight mean you have a complete understanding of it and can prepare a counter.
Meanwhile, almost every fight Gaolang and Okubo took part in is recorded from multiple angles in glorious 4k. They probably have fan wikis where people break down the exact speed of their individual punches. Everyone knows everything about them. Their only option when coming to an underground fighting ring full of secretive asshole with superpowers and ancestral techniques to break down human limits and special hits no living human has seen before and who also have studied every public match Okubo and Gaolang ever fought in preparation for this day is to be strong enough that it doesn't matter. Their only recourse is to Just Be That Good.
There's no magic trick to beating Okubo Naoya. Your first step is: You have to be faster, stronger, have more stamina, and have better technique than him. The Fang checks all these boxes. That's good.
Now you actually do still have to beat him.
Everybody has a plan until they get punched in the face.
Good luck.
