Harry Potter: Eclipse. - Chapter 24:

With the Legendary Mechanic System, I transmigrated to Marvel Universe to be Dr. Zola’s assistant.

With Mechanical Force Analysis, I can learn every black technology.

Winter Soldier’s arm? I built a better one for you.

Iron Man’s armor? I already made it a decade earlier.

Doc Ock’s tentacles? I am the one who provided core technology.

Hulk’s mutation? Sorry, I was there and got hit by the radiation too.

As for a certain purple potato, can he collect all Infinity Stones?

……

However, I only had one simple ultimate dream. That is to go home…

- Description from Novelupdates

Dropped

An alien race invaded the Earth on June 6, 2128. At the midst of this war, many nations allied with the alien threat and the war nearly wiped out the rebelling humans of the planet. At the edge of mankind's survival, the United Nations Army launched its forces to eliminate the immediate stellar threats that loomed over Earth.

General Seeker Carlean, commander and leader of the mission, risked and gave his life to destroy the immediate stellar threat. The battle was won though Earth lay in ruins. Perhaps mankind will live to see a few years of peace before the alien threat returns to wipe out their existence.

At the immediate aftermath of the stellar battle, the fallen Seeker Carlean awakens and finds himself at aged 17, living the peaceful life he lived 16 years before he died.

So begins a new game in the battle for humanity's survival.

“The sky was as clear as a wash, the sun radiated over the mountains and forests, and the entire world appeared tranquil, carrying a unique sense of stillness.Watching a person wearing a sexy tiger-print miniskirt, holding a stick, leading a group of more than ten people shouting as they chased after the leader of a fur-covered rhinoceros, Han Cheng couldn’t help but bring his slightly curled right hand to his slightly open mouth and once again exclaimed, ‘Oh my goodness!’(No system, no space, no cheating through crossing over, purely original primitive farming, without elements like cultivating immortality, for readers who enjoy a relaxed farming story, please read at ease.)”