Boris is here for revenge, who is now known as Boris Anderson. He's in search of the final object of a powerful Legend Sword. The awesome powerful Legend Sword makes any evil plan he controls with it that magically comes true, which happens to be the 'Adventure Time' toy (which PC Guy purchased from Walmart in the first film). When the entire city of New York City is put into danger, Eric and his friends (PC Guy, Victor, Jack, and Cayby) need to go on a incredible quest that takes them to Los Angeles inside the alternate live-action universe. In order to get back the toy and save their city in the 'Go!Animate' universe, the gang must retrieve the Legend Sword and transform themselves into a superhero league called 'The GoAnimate Masters'.