The Apocalypse Arrives, and I Master Fusion Technology from the Start

[Natural-disaster apocalypse + black technology + power fantasy + no saintly heroine + tech nerd + no supernatural abilities + no System]

Born into a wealthy family, Xue Cheng had everything his peers could envy: a comfortable home, a degree from a top university, and a job at the Chinese Academy of Sciences right after graduation, where he became a leading scientist. But just two years later, he was expelled from the academy, voluntarily relinquished his inheritance, sold off his assets, and became a disgrace to his family, cast out of the Xue household.

It was all because he detected a radio signal from space with a radio telescope and learned that the sun would soon expand into a red giant, increasing its luminosity by 2,000 times. Earth would then be knocked out of its current orbit and turned into a living hell. After learning the truth, Xue Cheng mobilized every resource at his disposal ahead of time, built a tokamak reactor, and constructed a doomsday fortress! He swore to be the final witness to the end of human civilization!