Halo is a game where you play as the Master Chief, the main character in the Series.

Info:

Master Chief: A Genetically enhanced super-soldier which was abducted by the UNSCDF at the age of six and sent to training. He has destroyed a number of Halo rings and is currently MIA.

Cortana: A "Smart" AI, Cortana was paired with Chief so that he could be more effective.

The Arbiter: AN honorary title that is given to an Elite who has done crimes to the Covenant. He is sent on a suicide mission. When he dies, a large number of forces are deployed to recover the armor. The Arbiter is currently on his homw planet.

Gravemind: The Gravemind can control the Flood and can gain access to others minds. The Gravemind was destroyed. On the Ark.

Sergeant Jhonson: He was Master Chief's friend. No one knew MAster Chief like Sgt. Jhonson. He is KIA.

Forerunners: The Forerunners have a major role in Halo. They were very intelligent and were able to do many things with that knowledge. They also created the Flood but the experiments went wrong. The Flood broke out and started causing mass chaos. The Forerunners tried to stop them but they couldent. The Forerunners ended up firing the Halos which killed them all. They passed their possesions down to the race that tey thought was most worthy: humans.

Precursors: An extinct race that was even more pwerful than the Forerunners. When the precursors went extinct, there powers went to the Foreruners.