In his original world, Delta Force was just a game. He was an ordinary college student with a KD ratio of barely 0. something, a total noob who never dared to play the hardest maps. He only went scavenging for low-tier loot in regular raids, surviving by playing it safe and stealing from others.
But after transmigrating to this world, he quickly absorbed every memory belonging to the original owner of this body. This world was almost identical to his previous life, with just one difference: Delta Force wasn't a game.
It was a real battlefield where national fortunes were at stake.