This is a sci-fi version of the last gunslinger :). He just gunned down his last competitor in the galactic gladiator tournament and is celebrated for his latest tournament victory.
I based the project on my alien armor sculpt I did a while back. It went through a bunch of iterations since. I tried different heads and helmets and the weapon changed twice. One interesting bit about the workflow, I started the gun in Zbrush and Modo and later found that Oculus Medium was way faster due to the extensive boolean options.