Help! System Apocalypse Logo (Patreon)

Going to create a System Apocalypse Logo and have a t-shirt made. I have a really cool idea, and want his on the front and something else on the back.... 

So, this has to be striking enough to be cool, but not overpowering since it'll be on the top left where a pocket would be. More discrete in front.  

Tell me what you think!