(On Hold) Sword Art Online: Not In It For The Glory

A boy, no older than 10, finds himself in an unprecedented situation, with the life of himself, and his mother, on the line.
This boy, will witness horrific actions that most would see as disgusting and outrageous, but they were not there to see what that boy had saw. This very boy, now lives in 2022, a hardened warrior, some may say murderer, but a warrior none the less. Technology has made a massive breakthrough, and the boy jumps at the chance to lose himself in the world of full-dive technology, and leave the world that had caused him to grieve for so long, and go through so much pain.
The man's story will be told, as he encounters new people in this new world, and may grow with them, to where his hard shell, may crack just a little.
In this world, this man is known as:
Monster Slayer.