Fan Fic / When Worlds Collide Mario Sonic And Mega Man Crossover

When Worlds Collide (formerly Heroes United) is a three-way Crossover Fan Fic between the Super Mario Bros., Sonic the Hedgehog, and Mega Man (Classic) series written by Nintendoman01. It can be read here.

Culex, the Dark Knight of Vanda, and his master, the Dark Mage, have plans to conquer the Mushroom World, Mobius, and the Earth of 20XX all at once. However, as environmental necessities prevent them from invading the worlds on their own, they turn to Bowser, Dr. Eggman, and Dr. Wily, arranging a meeting and subsequent Villain Team-Up between the three with the intent on taking over after they do their work. But what do Mario, Sonic, Mega Man, and their respective allies have to say about that?

Not to be confused with When Worlds Collide or the When Worlds Collide Series''.

When Worlds Collide provides examples of the following tropes (Beware of unmarked spoilers):

Alternative Title(s): Heroes United