Shotguns & Sorcery: The Omnibus:

Every night, legions of zombies scratch at the outer walls of Dragon City, trying to claw their way into the grim and gritty metropolis ruled over by the Dragon Emperor, the mighty beast that keeps the hordes of hungry dead from storming the place and tearing it to the ground. Inside, ex-adventurer Max Gibson — now "Freelance" — tries to keep his head down and enjoy his early retirement, but something keeps digging up parts of his long-buried past.

First he has to rescue an old pal from mur...