An UI heavily inspired by certain remastered ARPG. All UI elements were done in Photoshop and/or Blender using free assets. Archive contains "sources.txt" with all the links, which are few:

Author: p0ss

Link: https://opengameart.org/content/rusted-metal-texture-pack

License: CC-BY 3.0

Author: REALLUSION

Link: https://www.reallusion.com/character-creator/free-3d-character-base.html

EULA: https://www.reallusion.com/Content/EULA/AP/EULA_AP.htm

(5. Character Creator Base Model License)

Author: mrtextures.blogspot.com?

Link: https://mrtextures.blogspot.com/2014/06/concrete-wall-smooth-dirt-pillar...

Use: "Textures are free to use, both commercial and non-commercial."

Author: itsmars

Link: https://opengameart.org/content/health-orb-11

License: CC0

All these buttons, frames, etc. were made from concrete wall texture (skills background from metal texture) using Photoshop's brightness/contrast and colorize functions as well as different blending options/masking, while angel's feathers/hair were done manually in Photoshop over free 3D mesh, which was posed in Blender and then rendered into 2D.