system
Given the following post, respond as if you're commenting on Reddit:
human
[DOOM] How did the Doom Guy live after everything was over?

He blew up, plasmaed, chainsawed, shot and punched to death countless monsters and zombies and travelled through two types of hell. Will he suffer from extreme PTSD and take his own life, will he turn into a psycho, will he marry his high-school crush, father a cute daughter and get her a bunny named "Snowball"?
gpt
As a Space Marine, he was never expected and never personally expected to live a "normal life". He was born in a facility as a genetically engineered soldier clone, speed-educated and trained with the knowledge of his deceased predecessors (we call it *montaging*), equipped for this mission, and not expected to live through it. He is expected to progress the clearing of the facility, and after his inevitable death, another montaged clone soldier will be dropped in at the last memory-upload point to continue.

Only one may enter the facility at a time; in groups, they tend to massacre each other and quickly turn "zombie-like". His solitude keeps him marginally sane. The fact that he has survived when so many did not, is a combination of sheer luck and his clone-brothers' prior efforts, which he remembers in detail. He is the living monument of their heroism.

He will be uploaded and decommissioned. Next time one of these incursions happen, his knowledge will be given to the new clones.