MTL - Mr. Earnest Is My Boyfriend - Chapter 25 let's talk

One day, Zhang Fan, a poor medical student, receives a medical system from the future. This turns him into a new shining star in the medical field. Along the way, he must face medical corruption, competition, and infighting from other doctors, and even find time for a love life as he strives for the top of the medical field!

- Description from Novelupdates

Three thousand years ago, Bai Qiuran, who was extremely talented, was accepted as a disciple by the founder of Qingming Sect, and the young Taoist began to cultivate the path of immortality.

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.

He became stronger, faster than anyone else… but he lost. In the end, there was only despair for Kim YuWon.

In his last moments, he was given another chance… Through the sacrifice of his comrade, his fate had not been sealed yet.

Returning back to the past, he attempts to climb the Tower again with his unmatched talent.

To fight the ancient evils that threatens to destroy the Tower.