Sometime after Twilight becomes a princess and she and the mane 6 save Equestria. Spike has been starting to have strange visions that have been making him think about tons of strange stuff, Spike doesn't know what they mean, or if they're real or not, but it's caused him a lot of concern as time has passed by. One day, when he's in the forest to think to himself about all this, he's attacked by strange black creatures that came from the shadows, and Spike is saved by two strange weapons that appeared in his hands. And once he took them down, he saw a strange portal leading to somewhere else, and with too much in his mind of what's happening, Spike goes through it to see what may be causing this problem, and vanishes from Equestria completely.

Spike soon awakens in a world called Traverse Town, he soon meets a young boy named Sora, with a weapon like his, which is called a Keyblade. They both meet up with two other people named Donald and Goofy who came looking for them, and they're king. After learning of the monsters called the Heartless and the threat they pose, they all decide to team up and travel across from world to world, going through many different events and making new friends along the way. Spike never thought his life would change so suddenly, but now, he has to learn to master his new powers, and one day become.. a Keyblade Master.