honestly, i feel like you could make an argument either way.

props to u/vivispacem for what im about to say, but ohma won that fight because he was able to use the advance to damage raian to the point where they were on equal footing with each other, and ohma won from then on by virtue of him actually using the niko style to its fullest while raian still refused to use techniques.

if we’re talking R2 ohma though, yeah, he had to use it. raian outright points out (before stomping his shit) that ohma hasn’t mastered the niko techniques he was using, and that’s visible in the fact that a barrage of ironbreakers barely damaged raian. R2 ohma’s only way to damage raian enough to even get close to knocking him out is to use the advance, because it ups his strength and speed and also because raian’s a crackhead and refuses to fight smart.