MTL - The Rebirth of the Financial Hegemon - ~ please explain

Tang Zhen transmigrated to an apocalyptic world, where humans struggled to survive in various buildings that they built because the ground was covered in lethal dangers that were invisible to the naked eye. Tang Zhen transmigrated along with his mutated cell phone that was packed with miraculous applications.

There were all kinds of cities – some could fly in the sky, some could submerge into the ocean while some could become invisible – and shocking secrets were hidden within them.

The power of Tang Zhen’s city was…

He established a city and quickly leveled up his army with speeding tools. Then, he dominated this alternate world by seizing other cities.

He sat at the very top. Beneath his feet was a vast floating city guarded by dragons and surrounded by angels. Countless cannons were also set up at various corners of the city.

A million miles ahead, in the depths of the ocean, there was another city as large as a continent awaiting his conquest.

Being able to see into people's past has no real appeal for the teenager this story is about, letting him use it only as amusement and to show off when he was drunk.Never watch into someone's past beyond a superficial level.Never try to find out more than you should.NEVER. EVER. LOOK. INTO. THE. FUTURE.But everything changed the moment he was forced to look into the future, was forced to investigate a murder, and was forced to make the acquaintance of the victim's twin brother('s fists).The more time passed, the more it appeared that the primary reason for this murder wasn't a local problem, but a global one.This single, marred corpse was the beginning of a threat that would shake the world.(MC looses a screw when he enters the prison)BL, first-person view; MC is shuo (perhaps even a reversible couple); love interest falls in love first; both MC and ML are straight, mutual bending, Enemies to Lovers

On the brink of destruction, I regained consciousness and found myself back in the past, 20 years ago. In order to have a peaceful retirement, I must prevent the impending doom.