While Waluigi has a tennis racket, Ichigo has ZANGETSU. Zangetsu could beat his tennis racket fast while Ichigo could just knock him out hand to hand. Waluigi can’t compete in terms of physical strength. Ichigo wins.
Yoh has a giant sword that could beat Waluigi in one hit. Waluigi may have a tennis racket but that can’t save him. Not anymore. The only way he can win is if he got a super saiyan form. Yoh wins.
Shio has enough strength to easily take on a couple of Waluigi’s. Luckily for Waluigi things are looking a bit better for him. He only has a handful of losses and might bounce back. Shio has brighter hopes. Shio wins.
Ginta has a hammer that can take Waluigi down. Of course Waluigi has a car but not even that can stop Ginta. Ginta’s just too strong. Also he can summon The Gargolyeman. That is tough. Ginta wins.
Rallen has a lot of weapons to combat the enemy with. He has 10 different shields. 10 different sword, 10 different lances. 10 different axes. 10 different blasters. 4 different ships. And for Spectrobes don’t get me started. He has almost 100. Waluigi was doomed from the start. Rallen wins.
Kazuki has The Sunlight Heart lance that trumps Waluigi’s tennis racket. Kazuki’s sword skills are pretty good and later on he becomes worthy of being a Weekly Shounen Jump character. Because of this he easily beats Waluigi. Kazuki wins.
Optimus Prime has guns and lasers that can quickly beat Waluigi. Waluigi is weaker than Wario which is why Waluigi is doomed. He’s a winless man. Optumus Prime also has super forms. Optimus Prime wins.
Waluigi is Wario’s rival and buddy. He’s arguably a lot weaker but it’s hard to tell. With his cutting edge skills and the fact that he’s super tall makes him tough. However one beam from Frenzy and it’s all over. Frenzy wins.