I made a similar thread months ago and people seemed to think that Yujiro wins this against a lot of powerful OPM characters.
https://worstgen.alwaysdata.net/forum/threads/yujiro-hanma-vs-one-punch-man.1351/#post-100766
But I think we all overestimate a bit Yujiro here.
Yujiro is a mad beast. But Darkshine can take punishments far higher than what Yujiro can give. That earthquake punch is clearly an outlier and I think it was retconed for a part later (see someone saying that on reddit one day).
Darkshine is better in the punching and the tanking department by a margin. But I don't think speed wise that there is a big gap. Yujiro can punch faster than sound etc. Yujiro is hypersonic it seems.
Lets say speed equal : Darkshine won't really touch Yujiro. It will be like Bang all over again : Darkshine no damages but won't land a hit. Yujiro is the peak of martial arts too and he can use Darkshine strength to make him fly, to counter him etc.
Yujiro has also a skill stole to Kaku Kaioh that allows him to soften his body to help him take a hit better without breaking and then absorbing the power of the hit and hit back.
But I def think that if one hit of Darkshine connects it will break Yujiro in half.
Yujiro can maybe blind Darkshine by piercing his eyes but I don't think he can do real damages to Darkshine. But maybe "softer" places like eyes ears etc can be used.
So either stalemate and Yujiro will toss Darkshine left and right or Darkshine wins this. But it will be hard for both.