Gray Zone

Ryuen Kenshin's life has been anything but peaceful. He was born in an experimental facility, where they did body modifications on children and trained them to be super soilders. At age 7 the facility was raided and he was put in an orphanage. However the orphanage was pretty bad and he had to fight regularly. He grew up amidst a lot of violence, even getting involved with gangs in his teens. Eventually when he reached 18 years of age, he decided to turn his life around and joined the military, since he like the order they have. He eventually became an elite in the military and at age 28 retired, since he wanted to start a family. However due to an anomaly, he woke up in an 18 year olds body, with the same first name as him. At first he thought he was tripping balls, but soon things happened that was even more trippy. A zombie outbreak happened and Mana became a thing. Everyone recieved a system. Does he find the mushrooms that made him trip balls for multiple days, or does the elite soilder adapt to the new violent world? Heh, adapt? Who are we kidding. It's like a playground for him Mc is detached, cold- hearted and ruthless. He is also a huge troll and likes to joke around. He also has a brotherhood- like mentality, from the military, so the survivors under him are like his family/brotherhood. Mc will have casual sex, but if he will have a harem, it will be small, like 2 or 3 women. Not sure about making a harem though. World: Mashup from; High school of the dead, My first girlfriend is a gal, Black lagoon, Jormungandr and something else.