MTL - Rival In Love Says He Must Marry Me - Chapter 3 I will return with blood

The first great emperor in the world was betrayed by his confidante and perished. Millions of years later, the great emperor’s soul returned and was reborn as Ye Yan, the son-in-law who was kicked out by the Chu family with a letter of divorce, restarting the supreme journey. Open the gate of immortality, kill the Jiuzhongtian, and cast an invincible name again!

- Description from novelbuddy

Fu Hongxue was a cripple, born with a lame leg and subject to epileptic seizures. He was also one of the most powerful, legendary figures of the martial arts world, with a dull black saber that was second to none. His fame made him a frequent target of challengers, but whenever his saber left its sheath, only corpses would remain in its wake. One day, however, Fu Hongxue rescued someone whom he should have killed…and in doing so, set of a chain of events and a conspiracy that would rock the world.

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.