To those folks familiar with DC comics, this image probably strikes fear into your hearts. John Constantine wearing the helmet of Doctor Fate. It's like, Deadpool with an Infinity Stone.
Created in Clip Studio Paint Pro on a Surface Pro 4. Here's a look at my QuickPaint (tm) technique:
Here's the B&W line art only:
And the B&W line art with the glowy bits that were used as reference for the colorizing step but then later taken away: