Pentastic is one of the newer Good Lock modules, allowing users to customize their S-Pen experience. The latest update adds some custom backgrounds to Air Command, as well as brightness and blur control. After opening Pentastic, tap the style of Air Command you wish to use. Doing so will open up the editor, where you can upload an image that will serve as a background whenever you access Air Command.
Left: Background editor, Middle/Right: Edited backgrounds
Once you've selected your photo, you can add some blur, as well as adjust the brightness. If you don't want a background image, the brightness and blur sliders will still function. Personally, I think a transparent background looks best, especially if you lower the brightness and add some blur.
The update to Pentastic is available now on the Galaxy Store, as well as APK Mirror.