What would you guys do for a sidereal players side plot?

So i have a player who is a sidereal and if im being honest I dont really understand them super well past what it says about them in the core book, I know they mess with fate a lot and I know their role in overthrowing the solars. The other players I am not really struggling with but what would be a somewhat satisfying sidereal side plot? They are essence 1, I also dont know if any of them are on this subreddit so im gonna keep it vague if i can.