William Dunbar is a protagonist in Super Smash Bros. Crossover. In Season 13, William went along with Naruto Uzumaki, Gohan, Ben Tennyson, and Azula to fight against Sasuke Uchiha, Zombie Spider-Man, Fabia Sheen, and Psycho Kirby following their rebirths. In Season 22, William, Ben, and Azula follow Gohan and Crash Bandicoot without Gohan or Crash's knowledge, since they know Gohan doesn't stand a chance against the Dark Heroes of Legend. In Season 23, William is ambushed by Azula, but is unshaken by the ambush and is eager to make her pay for her treachery. In Season 27, William is repossessed by XANA once it is discovered that XANA was the one who brought the villains back to life.
William's appearance in the real world is based off his outfit from Season 4 of Code Lyoko. On Lyoko, William wears his Lyoko outfit from Season 3. When possessed by XANA, or when fighting in the real world, William wears his black suit.
- A running gag for William is that he is constantly getting possessed by XANA.
- While he does possess the Power Cosmic and the Balanced State, William doesn't use them as often as his friends do.
- For some reason, Sasuke was always unable to defeat William in a fair fight, despite the fact William is weaker than him. In Season 13, William was finally defeated by Sasuke.