As an animation, Bakemonogatari has a simple, clean art style. But the guest illustrations for the series are anything but simple! So, it's great to see that °Tens took on a more complex illustration and made it his own with vector gradients so fine at points it more resembles painting that vectoring. Do have a look at this beautiful wallpaper!
Loki Ragnarok needs more wallpapers and adult Loki even more ;
but just in case you are wondering it took a gazillion layers and tries to complete the cropped wings, serious restoration is serious u_u
Nice positioning around the moon, colors are a little funky, it doesn't seem normalized with the background, perhaps you could try using auto color option on photoshop next time! ^^
The background could look good, but the characters cover up too much of it to see much from it. Their wings and white parts of their clothes are too white as well, they could be darker to match the nightly sky and their clothes, and they could be smaller, so the background could be visible. Nice wallpaper though.