Master Chief (Halo)
MCPON John-117, or "Master Chief", is a fictional character and the protagonist of the "Halo" fictional universe created by Bungie. Master Chief is a playable character in the series of science fiction first-person shooter video games "", "Halo 2", "Halo 3", "Halo 4", and "". Outside video games, the character appears in books and graphic novels—"", "", "", and ""—and has cameos in other "Halo" media, including "", "", "The Halo Graphic Novel", "Halo Legends" and "".
Halo: Combat Evolved Anniversary
On the ringworld, the Chief rallies human survivors and leads a boarding party to rescue Keyes from the Covenant's clutches. Keyes reveals that the Covenant call the ring "Halo", and they believe it is some sort of weapon. The Chief is tasked with finding Halo's control room before the Covenant does. Once Cortana is inserted into the control room, she becomes alarmed and stays behind while she sends the Master Chief to find Keyes. While searching for the captain, the Master Chief encounters the Flood, a parasitic organism that infects sentient life. The release prompts Halo's caretaker, the AI 343 Guilty Spark, to enlist the Chief's help in activating Halo's defenses. The Chief's activation of the ring from the Control Room is stopped by Cortana, who reveals that Halo's defenses do not kill Flood, but rather their food in an effort to starve them—meaning that activating the ring would wipe out all sentient life in the galaxy. To stop the Flood from spreading and Spark from activating the ring, Cortana devises a plan to detonate the crashed "Autumn"s engines and destroy Halo. Fighting through Flood, Covenant, and Guilty Spark's robotic Sentinels, the Chief manually destabilizes the "Autumn"s reactors and he and Cortana narrowly escape the destruction of the ring via a Longsword fighter.