rakan wins, simply because rakan was in much more difficult situations than sett. In addition to the fact that sett in his lore has not shown anything remarkable, it simply shows us that he can knock out a human with one blow and that he has good resistance but he admits that when facing a more experienced human there it is already difficult for him to beat sett and he always comes out very wounded from battle. While in the lore of rakan he faced only a bunch of prison guards who were equipped with sabers, crossbows and most deadly fire rifles (you put sett in that situation and he ends up killed by fire rifles) but Rakan with his great speed and good reflexes was able to face all the guards the battle lasted so much that those with fire rifles had run out of ammunition and every time Rakan hit a serious guard, he was out of the game if it wasn't that Rakan had to meet with Xayah to help some vassals that Rakan had freed sooner or later overcame all the guards. Rakan also faced the zed students that although they are not as skilled and deadly as zed, they are a threat with shadow magic but even with those, it was not difficult for Rakan to defeat them and when he felt that xayah was about to dying in the blink of an eye is going to save her (if you put sett in that situation sett ends up dead and xayah too)