what is master chief (halo)?
He  is a fictional character and the protagonist in the "Halo" multimedia franchise.
Master Chief (Halo)
is a fictional character and the protagonist in the "Halo" multimedia franchise
wiki:12297450
Master Chief (Halo) [SEP] Introduction
Master Chief Petty Officer John-117, or "Master Chief", is a fictional character and the protagonist in the "Halo" multimedia franchise. Master Chief is a playable character in the series of science fiction first-person shooter video games "", "Halo 2", "Halo 3", "Halo 4", " and Halo Infinite". The character also appears in "Halo" books and graphic novelsincluding "", "", "", and ""and has minor appearances or cameos in other "Halo" media. Master Chief is a towering supersoldier known as a "Spartan", raised and trained from childhood for combat. He is almost faceless and rarely seen without his green-colored armor and helmet.