Kenshiro goes through the Hero Association (One Punch Man) gauntlet

[FrenchGemini]

He starts from the very bottom of C-Class as a warm-up (duh!) to the top of S-Class, if Hokuto Shinken's 2000-year-old history allows it. Obviously, Saitama is moved at the very end of that gauntlet, and Ken doesn't get to fight King, because we know that even Hokuto Shinken can't do anything against the King Engine , or Blast, because we don't know much about this guy. Ken is fully rested and healed before each fight.

Where does he stop?

Bonus: Same as before, except that Kenshiro now gets to activate Musou Tensei before each fight. How much does it change the gauntlet?

[Cthulhu_of_R'lyeh]

They are already dead.

... memes aside, the buck probably stops at like. Genos? Unless Kenshiro is notably faster.

[Guy1]

Pig God is getting the Mr. Heart treatment isn't he?

[Kuro]

Kenshiro takes Mumen as the next successor to Hokuto Shinken.

[T51R]

If Ken manages to trigger Muso Tensei in time, nobody is safe. Except Genos, because he has no pressure points. And IIRC Ken has never faced a full cyborg before.

[Nik Hasta]

I'm going to assume we can just skip to S Class so... to do them in the order of their placing in S Class.

17. Puri Puri Prisoner.

He's a fairly conventional enemy. Ridiculous durability and damage soak but Hokuto Shinken should bypass that just fine.

16. Metal Bat

Again, fairly conventional. A better fighter than Puri Puri he gets stronger the longer the fight goes on but, again, Ken only really needs to touch him once and he's done.

15. Tank Top Master

See above. He's not really a problem.

14. Genos / Demon Cyborg

Tricky. As others have noted, his robotic body means a significant portion of Ken's offensive options are rendered moot. I don't know how the phase fist would necessarily impact on Genos' internal workings, probably wouldn't do anything good to him but it would likely be less effective. This means that Kenshiro is forced to do this manually. Genos is also a hell of a lot faster than the others, probably not fast enough to blitz Kenshiro but he can basically fly and has ridiculous firepower.

Ken isn't without his own ranged options but Genos can blow away buildings with basically from-the-hip type blasts. There's not a good reason for him to close distance really which means Ken has to chase him down. Ken is functionally fireproof based on the number of times he's been blown up or stuck in buildings that are on fire and whatever and his natural Touki defences are ridiculously high but Genos is capable of really high levels of firepower, especially with his most recent upgrade, so it's a bit moot.

In short, if Genos is overconfident and goes for hand to hand, he's going to get messed up. Ken is astronomically more skilled than him and his mastery of Nanto Seiken techniques and his sheer hitting power means that this would go poorly for Genos. If he plays keepaway and just tries to nuke him off the face of the earth, Ken is going to have a hard time overcoming that with his less effective long range game.

So yeah, not impossible, but not an easy fight for Ken. Advantage Genos certainly.

13. Flash Flash

So, as of his fight in the redone manga against the fire and wind ninja, we really got an idea of how ridiculously fast Flashy actually is. The Hokuto no Ken alogrithm is pretty deep but I'm a bit dubious on Ken being able to actually match him in speed outside of... theoretical amping through Raibo Shinkyaku. I would say that it's advantage Flashy. This means Flashy just has to work through Ken's ridiculous durability. Now, Ken could do what Raoh did and just go with a destructive Touki field in lieu of active defence but he can't maintain that forever. As per usual, he only needs to touch Flashy once to utterly ruin him or cripple him but getting that hit might be challenging.

He could go with like... a mutual takedown and trust in his regeneration and durability. Take a deliberate stab, trap the sword with his abs or something and then rip Flashy apart with one hand.

Again, not impossible, but a tough match up for Ken.

I'll press on because it's not impossible for Ken to take this and the gauntlet actually gets easier for a bit from here.

12. Watchdog Man

Not many feats but he's ostensibly human and is capable of toying with a pre-evolved Garou with ease. I feel like Ken can take him pretty easily.

11. Superalloy Darkshine

Ken is pretty much built to mess this dude up. He prides himself on his muscular defences and Ken is built to make those irrelevant. This goes very poorly for Darkshine.

10. Pig God

Ken already beat this dude when he was called Mr Heart. Fist of Soft Strikes and then pressure point him to death.

9. Drive Knight

Basically the same issues as Genos but with considerably more utility and he can actively transform to cover damage in a way that Genos can't. He also seldom seems to actually go for direct assaults, using more gimmicks and specialised weaponry and so on. Ken is really not built for this, so in my view, this is the hardest stop for Ken. I could envision him finding ways around Genos' abilities because Genos is pretty limited in terms of what he does and he's flatly not that experienced, Drive Knight is calculating, way more tricky and more adaptable. It's matchup bad folks.

8. Zombieman

As I don't think Ken makes it past Drive Knight, I'm mostly just doing this one for fun. Zombieman will just keep getting up. Ken literally can't win outside of a ten count.