My Ex-Girlfriend Was Appointed as a Knight Commander - Chapter 183: Side Story 1. Master and Disciple

Violet skies, a world undergoing massive changes, a deficient moon, interlinking voids…
When the world experienced a cataclysmic event,the majority of living things ceased to exist. Although humanity survived by hiding in the last safe zones, humans had to face mutated dire beasts and colossal source beasts that could break through the space barrier and enter the earth at any second.
Luo Yunyang, a young man who grew up in those calamitous times, obtained an attribute regulator and set out to walk the path of supremacy!

- Description from novelupdates

Year 2056, in a city in the Yuan Jiang Su Jin area. On top of a ruined, shattered six story residential apartment sits a teenager wearing a combat vest, militaristic trousers, and alloyed battle boots. On his back is a hexagonal shield and equipped is a blood-shadow battle knife. He sits there silently on the edge of the roof. At this time, the sparkling sky was shining and there was a refreshing breath within the air that blew towards him. However, there was only silence within the ruined, deserted city, with an occasional howl that makes your heart skip a beat.

When a struggling graduating student failed his capstone project, he got frustrated and attempted to take his own life. The moment he was about to take a leap, a voice stopped him and handed him a strange box and disappeared.As he got home, he opened the box and saw a strange usb device and a set of strange pills. Later he found out that the USB contained inventions from the 20th to 23rd century, and the pills were a nootopic drug.With this discovery, his life would soon change from an outcast of the family to the world’s powerful businessman that would create companies that would rival top companies around the world.

Our straight (?) bottom woke up ten years into the future and found himself on the bed of his childhood friend… At the start, the bottom was shocked to his very bones, but he soon quickly accepted this premise and found the whole situation to be rather amusing. Precisely then, the bottom once again went back to his timeline — back to when he and the top were just platonic childhood friends.