Headcanon
1. Soul is a snuggler in his sleep. This leads to much awkwardness in the morning if he's sharing the couch with Yuusuke.
2. He's scared of heights. And spiders. Headcanon says Wes played a trick on him when they were younger with a fake spider, something Soul keeps secret about since he's supposed to be a cool guy. And let's face it, cool guys aren't scared of spiders.
The heights thing is mainly because I want lulz when Hiccup takes him for a ride on Toothless :D
3. Speaking of Wes, he shares a normal relationship with his brother. It's only that half the time he suffers low self esteem because Wes is just that much of a better musician than him. He's a pretty cool bro otherwise.
4. Soul knows how to cook. And I mean cook. His specialty is mostly desserts though.
5. Soul's family lives in England and are filthy rich/well known to the public, but he definitely prefers the quiet life in Death City to that shit. It was awkward moving at first but he got used to it.
6. Totally a Type A tsundere. He's a jerkass a majority of the time, but harm his Meister (or any of his friends here really) and he will go BERSERK.
7. He can ballroom dance, primarily because of his upbringing, but like most of the other things connected to his family he won't show it because he wants to forget about it.
8. He has a soft spot for grannies. It's sort of stated in canon that Soul and Wes had a good relationship with Grandma Evans, so I imagine he's quite tolerable of old people.
9. Closest friends in SP are Tenten, Danny, Rapunzel (dropped), Yuusuke, Hiccup (dropped) and Veser. Though of course, he's not going to admit it.
10. Headcanon says he's never seen a movie in his life. He just knows the music from the soundtracks.
11. He likes cats. Whether this is because of Blair or not is an entirely different situation.
12. Thanks to training with Tenten and Neji, he's gotten faster and more accurate when working by himself. He still fucks up though.
13. Headcanon birthday is August 16th. This is the birthday of the guy he supposedly gets his last name after (Bill Evans).
14. It's not that he doesn't like playing for people, he just fears the criticism of the trained ear. He's always been second rate to his brother, who's considered a very talented violinist in his world and has built his career whereas Soul pretty much left the family after finding out he was a Demon Weapon.
15. Favourite food is strawberry shortcake. Completely from a Soul/Maka doujinshi where Soul had a fever and asked Maka to make him strawberry shortcake.
16. Another motorcycle enthusiast here. He owns a Kawasaki Vulcan (or something similar) in canon and bought one with money he saved from missions here in SP.
17. Soul prefers flat chests over big breasts. If chapter 73 is anything to go by.