Finally finished! 

Went full demon-mode with Mei, cause she a DEMON.  

 I actually spent about 30% of the time spent on this trying to get the colors to look satisfactory.  It's really hard to bring in too much color while keeping the monochromatic ink brush feel.  

Edit: Finished the Tracer x Mercy:
Overwatch to the West!! by RobotCatArt