Biro Art - Ballpoint pen drawing of geisha v demon

This is my first piece of biroart. Of course I've used biros before for doodling and writing, but I've never attempted a proper piece of pen and ink artwork. I like the blue colour of the pen and the range of lines it can make from bold to very faint. I used watercolour paper and a light box beneath which was my pre-drawn pencil art.
I made a bunch of mistakes and overcooked the shading in parts so I definitely have lots of room for improvement. I intend to draw more biro art pieces so hopefully they will get better over time.
The whole drawing I think took me around 8-10 hours - about three evenings of work.