People act as if a sports-based set and a personality-based set are mutually exclusive and that's pretty laughable, not gonna lie.
Cheating and deception make up a large part of Waluigi's personality, but Waluigi literally debuted in a tennis game. Even his Assist Trophy calls back to this; it shouldn't go ignored in his moveset. A good Waluigi moveset, IMO, has four major tenants: tricky movements, dancing, sports, and copious amounts of Dïck Dastardly-esque cheating. Something like pulling out a Fake Item Box from Mario Kart that stuns opponents if they touch it is perfectly in-character. It's a deceptive trick that gives Waluigi an edge over the opponent, and calls back to his spin-off origins. Using Rally and Zone Shots from Mario Tennis Aces is another example. Waluigi would have a greater window of time to hit the ball back at the opponent than the opponent would have to try and reflect it, once again fitting Waluigi's personality, Zone Shot's actual function, and his tennis origin.
Saying that it has to be either sports based or "personality based" is a blatantly false dichotomy; his personality is informed through sports. He's a hyper-competitive cheater.