Spartan 117- John

The main character and hero of the Halo series, John is the most formidable infantry unit in the universe (presumably).

John was a just a regular boy with a lucky streak and excellent fitness before he was abducted by the military and a flash-clone put in his place. John went extensive military training from a very young age, along with the other members of the Spartan program. Once they were old enough, the already elite Spartan units went through an extreme physical augmentation, their bodies were turned into more than perfect fighting machines. With increased reflexes, vision, stamina, strength, mental quickness, the only thing the young Spartans were lacking was firepower.

In halo 2 the chief is equipped with Mark VI Mjolnir armor, which drastically increases the strength, speed, reflexes, vision, and communication abilities of the wearer, never mind the shields and armor that nearly make the chief invincible.