I've played most of miHoYo's games, but Lumi's wallpapers are still my favorite since they're more customizable. You can change Lumi's outfit and the color of the background. Also, Lumi's wallpapers aren't just a standard loop! When you first apply the wallpaper, she either taps on the screen or spins around in her chair to greet you. She puts on headphones to listen to some music, falls asleep sometimes, and more. She does these things in no particular order. She just does random stuff while sitting in a chair, yet she's still extremely adorable!
TL;DR: Cute live & static wallpapers of characters from miHoYo games. Lumi, the app's mascot, also has her own awesome wallpapers. I 100% recommend!