XANA is an artificial intelligence and a main antagonist in Super Smash Bros. Crossover. Like in Code Lyoko, XANA wants to destroy the Lyoko Warriors and now all the heroes as they are a nuissance to him. Ever since William Dunbar was freed, XANA has been attempting to recapture him, which is used as a running gag. XANA acted as a double agent, working for the League of Villains and the Koopa Troop before they merged in Season 4. XANA has the ability to possess people, though if they've been on Lyoko, he can't possess them. In Season 27, it is revealed that XANA was the one who recreated the League of Villains and the Nomadic Mechtogan, making XANA the primary antagonist of Season 27. Once Iron Man discovers this, XANA uses the opprotunity to repossess William and Azula before revealing himself to Iron Man, declaring that the heroes cannot win this time. Despite his increased abilities, XANA is destroyed when Aelita uses Excalibur to initiate a mass tower deactivation, putting an end to the malevolent A.I. for good.
- XANA is the only character that cannot talk as he is a computer program. Instead, he beeps as a form of communication. However, in Season 27, XANA communicated through William instead.
- Neither Sasuke or the Axem Rangers X were aware that XANA was a double agent for both sides.