After Spirit Tracks, Soul had the ability to project herself out of her body into her ghost form, leaving her body limp wherever she left it. While now she longs for adventure or to at least roam other than the castle other to the town for a special event, the King keeps her under the castle, under heavy guard and heavily protecting her, including forbidding her to leave the castle grounds. Because of this, she often pretends to fall asleep, projecting out of her body and following Spirit around, as he is one of the few that can see her like this.
After the adventure, the two tried explaining this new ability that Soul had gained, but nobody believed them as they were just twelve year olds. Hero and princess they may be, but children will always make things up for play in their eyes. This results in the castle workers thinking that there is something, maybe a condition, that makes Soul require much more sleep than usual.
The only ones that can see her in ghost form are the ones who can in game, otherwise no one else can see her in this form, not even any of the other Links other than spirit.
Her eye colour was also effected by becoming a ghost as shown in the image above
(I tried using the alt text feature for this post, how was it? It's my first time using it so i hope it was okay, if you think i should add this to all of the previous posts on this blog and any future ones, please let me know?)