In the apocalypse, I have a flying house with unlimited upgrades.

An unknown calamity swept the globe, with hordes of mutated zombies proving ineffective against conventional headshots. The reborn, mistakenly believing a second chance at life would rewrite their destiny, recklessly ventured into a post-apocalyptic shelter, only to find themselves facing an even more severe survival challenge. As mutated zombies engulfed the world, even hundred-meter-high walls couldn't halt their advance. When despair gripped humanity, a floating fortress appeared, offering a final glimmer of hope. …Xu Shuai unexpectedly acquired a flying house, which, once activated, could be infinitely upgraded. He could also develop potions to enhance his physique, new weapons, and special combat suits. So, he upgraded his flying house, expanded his territory, increased his altitude, cultivated crops, raised animals, recruited talented individuals, and sounded the horn of counterattack.