Mirabilis has a remarkable gift for composing portraits with vivid colors and dramatic poses. Robin is my favorite because the character is so dramatic and alive. Stylized realism is often more effective than trying to capture every pore on facial skin. There's a tired look in the eyes (which are beautifully wet) that suggests Robin hasn't had any sleep for a long time. I love the punkish aspect to the character with the hair blending (red to black) which is perfect. The central light source is right in the middle of the face and makes the portrait so very dramatic.
Mirabilis has dozens of these kind of dramatic portraits in his/her gallery. I highly recommend you visit as you will find a world of fascinating characters.