A Clip Studio Paint (Manga Studio 5) brush meant to simulate side pencil sketching! Requires a drawing tablet that recognizes direction and tilt, and (maybe?) a relatively up-to-date version of Clip Studio Paint!
WARNING! It may take your brain some adjustment to use this, as we don't typically use digital brushes the way this one works. Try to imagine it's a real pencil on it's side. The angle and direction matter!