Noble Six. The ultra-lethal, quiet-type member of Team NOBLE. One of two surviving members of Team NOBLE. He was in his last stand, fighting for his life, seeking to kill as many Covenant soldiers as possible before his demise.
The Doom Slayer. The bane of hell itself. The only human to make it from the mortal realm to that of hell and back. The man with no fears. He fights his way through to the Cyberdemon, the only thing separating him and saving Mankind... or, worst-case-scenario, what remains of it. He will fight to save Earth, even if it costs him his life.
Logan. A master of stealth. Guns galore. He's silently disassembling DedSec's latest target- and nearest major Blume building- a gang that transports illegal drugs across the east coast of the U.S.
What binds all three of these together? Why and how are they so similar? They all wear masks and fight for what they believe in. Noble Six believes in a better future for Humanity. He fights for the United Nations Space Command.
The Doom Slayer believes in the same thing. He slays demons using his arsenal with the assistance of Dr. Samuel Hayden and VEGA, both part of the Union Aerospace Corporation.
Logan believes in a safer future for humanity, one with less worries. He represents DedSec... or used to, before he was cast out for a mission completed with a dangerous level of recklessness.
These three are, or used to be, lone wolves. But a cosmic force will bring them together and force they who fight alone to fight together.