Doomsday Swap: My Cellar Opens into the Three Kingdoms

[Dual transmigration + Three Kingdoms + Apocalypse + Farming and Conquest + Core Crystal Evolution + Base Building] Three years into the apocalypse, monsters roam unchecked. Core Crystal evolvers lord it over everyone, while the base cities treat ordinary people as disposable resources. Lu Chuan hides with his gravely ill younger sister in their ancestral home in a small mountain village. He thinks they won't make it through the night, until he pushes open a door deep in the cellar. Beyond it lies the chaotic Three Kingdoms era of Jian'an Year Two. What's your biggest regret about the Three Kingdoms? What do you want to do? That's for you to decide.