Landon is clearly the superior fighter in terms of power and defense. With a total power and guard score of 40 compared to Wower Sans' total score of 1, Landon could easily overpower him. Also, Landon's skillset of being able to dodge and adapt to enemies makes it very difficult for Wower Sans' speedy attacks to land a significant blow. And although Wower Sans may have a powerful hole attack, Landon's survival of a black hole and 5 nukes prove that he is not easily defeated. In short, Landon would win due to his superior strength and adaptable combat skills.