The next exciting chapter in the Sonic/Mega Man "Worlds Unite" crossover event starts here! "Worlds Unite," Part Five: The worlds of Sonic and Mega Man have been joined together by Sigma, and it's going to take a full-on army of unified heroes to make it right! Scratch that, it's going to take some heroes and some villains! When the mysterious and malicious Xander Payne inexplicably arrives with Drs. Eggman and Wily in tow, our heroes get new insight into Sigma's plans!