If one day you discovered that you were the only person in the world who knew the story of Arknights, and that Arknights had become an online game, what would you do?
"Doesn't that make me a Contingency Contract veteran? I'm going to crush it!"
"I'll kick Mephisto, punch Patriot, and crush Theresis's ambitions!"
After Xia Liu entered the world of Arknights and made some progress there, he realized something was off.
"Wait?! Weren't you all saying this was just an online game?!"
"And why have your affection levels gone past the limit?!"
PS: The core setting is the world of Arknights, with crossover elements.
PS: The blurb is a bit misleading (slips away).