Everything popular has it's parodies. Halo has RvB, Star Wars has god knows how many, Jurassic Park, LBT, you name it, somebody's parodied it. Who's to say and RPG can't be parodied, too? Here it is, In Darkness, parodieitiezed.
Use your characters from In Darkness, and any other characters you want.
There is no limits, aside from no character-killing.