In Cartoon Network Punch Time Explosion XL, Vilgax is an obvious S tier. His down smash is way too powerful, and is the fastest normal move that deals 20+%. His down smash is so powerful that it outdamages Kevin's PTE attacks which already have really slow startup to just shield. In the hands of a professional who masters the character, you bet he's a dangerous S tier pick. In fact, without any competitive ruleset in mind (all stages, items+assists, free for alls, basically anything goes) Vilgax is overall the best character in the game as he can adapt the best in whatever rules you throw at him.
In this video, I'm not even warmed up and don't really try because that's how easy he is to play. Some matches I opt out of using down smash.