Kid Icarus: Chaos is a fan-made game idea where you play as Pit. It is very similar to Uprising, but the main villain is the Chaos Kin reborn. You also have more chapters where other characters are playable. Making guest appearances are Popo and Nana from Ice Climbers, with Popo being playable in a few chapters.
The story is based around chasing down the Chaos Kin and preventing him from taking people's souls away like he did to Palutena in Uprising. Pit meets many friends, yet it seems those friends' souls are taken away just as soon as Pit meets them.
In the first chapter, Pit gets a taste of that when Magnus's soul is taken away from him. Others who get their souls taken are Dark Pit, Viridi, Phosphora, Cragalanche, Popo, Thanatos, and Palutena.
In the end, Pit defeats the reborn Chaos Kin, but at a cost. Pit loses his own soul and the Chaos Kin infests his body. As Pit's fallen friends get their souls back, they realize what needs to be done.
For the next few chapters after that, you play as characters such as Popo, Magnus, and Dark Pit as they try to chase down "Chaos Pit", defeat him, and allow Pit's soul to return to his body. The last chapter is a big boss battle with "Ultimate Chaos Kin." Everybody helps in this fight, so it may be one of the easier boss fights with the Chaos Kin.
After it all ends, the heroes watch the sunset on the horizon, at ease that its all over.