Waluigi is the strangest enemy, and only hates AGK because he called him skinny. But in his defense, he was just pointing it out. He isn't a villain actually, he just hates AGK. In episode 12, it now finally ends when Crazy Dave tells them to truce. He has a special attack where a giant Waluigi appears in the background, and then Waluigi picks his targets he wants to explode in traces of fire. This attack sadly failed on Angry Sun. He used to be a magician but that was thousands of years ago.
Note: He can teleport, he has done it in the Backrooms. It was a sneak attack on AGK, before Waluigi got hit by 4 glitching cars crashing into him. At this point he's become a pal to AGK. Heck, he's even helped him with Arthur.exe.
When he battled with Angry Sun again, he had to think smart. He used a couple Heavy Blocks to attack him, it worked quite well. Angry Sun sent him in burning lava to finally kill him off, but Waluigi knew this was gonna happen. He used material of Heavy Blocks to put into his clothes and survive. He even is always prepared. When Giga Football Player Zombie attacked him, he had a Light Block to fly away.
When AGK's family went to sleep... well kind of. Leonidas was doing his own thing. He had coupons for a free restaurant, and was willing to have AGK come with him. He even invited AGK to this party house. Things get a bit dark from here though. As he has to live in the party house for a bit cause of Scarlett attacking Linkin Park. He saw her target list, and he noticed he was on it, and Harry was crossed with an X. He even saw AGK's name on there. He even helped AGK get to school.