These images came out of a marker and pro-white demo last week in my class. I had a request to post it up with original lines, markered version, and how I alter it in Photoshop to finish it.
with some level adjustments, grunge overlay, color adjusted more blue, bg gradient, and a little brightening of the eye

prismacolor markers 10%-40% and pro-white

blue prismacolor colerase pencil with staedler mars tech pen 0.1