I second every mention before.
My advise. Dont fiddle too much with his visuals at this point. You are clearly skilled with your tools. Its pretty much unimportant wich hairstyle or look you display him at first. This is a sort of developement that will take place over the battles you hopefully will show us in the future.
Concentrate on the character itself. Dive into him and go below the superficiality.
A good technique to get to know your character better are little question lists like these. http://tekkysfurries.tumblr.com/post/137069221442/get-to-know-me-uncomfortably-well
This is not the best sadly.
As mentioned before try out in comic form or just sketches how he would interact with other characters (of your choice though void ocs would be easy). Its like getting to know a stranger. But this stranger is your stranger with a cane.
The moment you feel your character as someone who could be actually real (as much as some stuff can be real *cough) you have it way easier to draw for him and to do comics.