Reaper's Resurgence: A System Reset - Chapter 10B1 | - Quantum Displacement

Once a live-in son-in-law, humiliated and looked down upon, he accidentally awakens a heaven-defying Eye Technique.From that moment on, his life takes a drastic turn. With peerless medical skills, x-ray-like vision, unmatched martial arts, and mastery of elixirs, he crushes all enemies in his path.This is the rise of the man they once called worthless—now unstoppable and untouchable.

Wang Zhong arrived in an alternate world and became embroiled in this world's global war.What he gained was a cheat, akin to a real-time strategy game's overhead perspective, and he could even see through the eyes of his subordinates' units!So, he decisively started micro-managing, “Shift the machine gun position five centimeters to the left! Place the anti-tank cannon in the forest on the right!”Three years passed in this manner, and Wang Zhong looked at the marshal's baton in his hand, then at the double-headed eagle flag behind the emperor's envoy.“In my hometown, there's an old saying, 'Princes and generals, are they not sprung from the masses?' Envoy, do you know of it?”

I became the childhood friend of the protagonist in a novel. The childhood friend who died from taking drugs.

Xia Zhijun got the title ‘study god’ after scoring first place in the whole city. He’s the model of a good student in a teacher’s eyes: good grades, good manners, and quiet. When he wasn’t smiling, his entire body emits a cold abstinence aura. The girls only have the guts to look from afar and not get close.
Later, it was rumored throughout the entire school that even the study god would fight and hit on girls. Whoever dared to provoke his girl, he would teach you how to be a person at every minute. The night of the graduation ceremony someone saw him blocking Gu Siyi in the corner. He didn’t stop kissing even when she cried. He bit her lips and said in a raspy voice, “I’m going crazy…”
During college finals, Gu Siyi almost bursted out crying, “I’m such a failure. I won’t be able to find a good job in the future…And if I can’t find a good job, I can’t provide for myself…”
Xia Zhijun played with her pink earlobe and remarked, “I’ll take care of you.”
After they graduated, Xia Zhijun created a research company and Gu Siyi became the boss’s wife.
The commercial rocket, “Star of Siyi” was successfully launched. So everyone knew that the new technology superstar, Xia Zhijun has a wife who he spoils a lot.

- Description from Novelupdates