Sargeant Blazkowicz is the subordinate of Major Kira Morgan, and is part of her squad along with Riley O'Connor, the Marine squad's resident scientist. Their squad was sent to Tycho Station on the Moon in preparation to research events on Mars to learn more concerning the Mars Incident. But they encounter a new incursion on the moon, and are forced to travel to Earth, and Hell itself.
Personality and traits
Unless you play as Sarge he is the strong quiet type and the beginning Morgan chooses to show at behind he says nothing. If O'Conner chooses to stay behind he also remains silent. He only speaks up if he chooses to stay behind.
He apparently does not know of his relatives survival in the Mars Incident a year before. UAC's public released records only indicate there were 'no survivors' (the real truth was classified).
Titles and Nicknames
Behind the scenes
He is not the Marine (Doom's protagonist) in Doom RPG/Doom/Doom II/Doom 3 (B.J. Blazkowicz III) or Doom 3 novels (John Kane) who after being found little information is known after the events of that games/universes (there are allusions to events of Doom 3 occurring in the same year as Doom RPG or as a prequel to Doom II RPG, at least in the RPG universe). The official site for Doom RPG states that the Doom Marine is the same one from Doom, Doom II, and Doom 3, and that it represents a 'return to Mars' (a nod to events of Doom 3).
However the Marine of Doom II may or may not be the same character or a separate character (giving the possibility he's actually Stan) from the Doom I character depending on different manuals and websites. His backstory differs from that of the original Doom character in that he fought on UAC Mars Base and escaped in a drop ship. Whereas as original Doom character fought in Phobos and Mars and in both oginal Doom and Ultimate Doom reaches earth via transporter gateways. Although this would also technically fit the "return to Mars" reference for this character as well, Stan in comic never was on Mars during the RPG's Mars Incident and separate from the hero in that game.
Depending on which character is chosen, the other two leave with Caldex to take part on their own paths through the base. Stan's last name is a reference to the protagonist of Wolfenstein William "BJ" Blazkowicz. This means perhaps that Stan and B.J. Blazkowicz III are related somehow.
An individual mentioned in a log in the Entrance (Doom RPG) is also named B.J. Blazkowicz (Doom RPG) in Doom RPG. An obvious easter egg. It is unclear if the message is addressed to another individual or the Marine player character. The latter is possible. The message directs he player to a secret hidden room in the Entrance holding a shotgun.