Atlas (A.k.a Marcus Adler) is the older brother to William Adler on Fireteam Spectral. Speaking in a kind, and somewhat sentimental tone. Atlas is able to bond and get along with nearly everyone from his approachable demeanor. However he has a very somber tone to him, especially around Adler. Leading people to suspect there is more under the surface.

Atlas is a former experienced EOD operative, Although he is stationed along side Lawson (Whom watches over Spectral and his brother). Atlas is still an experienced soldier, but he prioritizes his brother and their relationship. Through the themes of brotherhood that is present in this series.

However under his demeanor lies an emotionally distant trainwreck that is hiding a secret about his past and his brother. Driving him to do whatever it takes to protect Adler in the best way he can - and in the ways he knows how.

Atlas is a minor character this season, how he goes on to become a large part of the wider story, that will later go on to become apart of an ONI spartan sector known as 'Sword'.