John, along with other SPARTAN-IIs, was augmented with various things. Not all SPARTAN-IIs survived, however. The survivors gained enhanced speed, strength, stamina, and agility. They were excellent tacticians and leaders due to their teaching of nearly every historically significant battle, and then some. In the end, though, John was lost after the destruction of UNSC Forward Unto Dawn. He was a hero, and died saving humanity.
Meanwhile, he has been mocked across the internet for the Halo story being poor and him being a 'fail'. While the story is not the greatest, surely it is not the worst, or it would be so bad it's good. Of course, your mileage may vary...
Please do not confuse with Mister Chief.
"all eight lolololololoolol fuck u"
"Hmmm, this "Master Chief Petty Officer John-117" seems quite similar to other video game heroes."
"hai r u mster chif?"
"no im not a chef lolololololollollololooll1111"