Betrayed & Reborn in the Apocalypse: Alien Tech, Billions in Supplies, One Mega Fortress!

What the story is about

After dying during eight years of apocalypse, Lee Fan is reborn before the disaster and uses his foreknowledge, a hidden dimensional space, and help from the alien intelligence Linlin to stockpile supplies and build a fortified base. As society begins to collapse, he prepares for the coming catastrophe while confronting old enemies and the growing dangers outside his shelter.