MTL - The Divine Martial Stars - ~ 17, tearing the face

When an S-class elite assassin-raised captain of a special ops suicide squad comes home from a high-stakes Africa mission, he finds himself offered something that could potentially set him up for life- a curious assignment that he could use to finally exit his days of war and slaughter.

This is the novel behind the TV series, “Love Like the Galaxy”.
The following synopsis is based on the TV Series.

“The young Cheng Shaoshang was left behind because her parents had gone off to fight in the war. In order to protect herself from her scheming aunt, she had to be extra diligent while pretending to be the opposite. However, years of estrangement have made it difficult for them to become family again.

Lacking love her whole life, Cheng Shaoshang is both pragmatic and insecure in choosing a partner for marriage. She encounters three men – the emperor’s adopted son Ling Buyi, the talented Yuan Shen of Bailu Mountain, and the aristocrat Lou Yao who each have their pros and cons. Although the road to love is bumpy, she never regrets every choice she makes. Through her interactions with Ling Buyi, she unintentionally becomes involved in the mystery surrounding his family and his identity. The two grow from their experiences and worked together, upholding the righteousness in their hearts to resolve a national crisis.”

- Description from Novelupdates

The end of all worlds approaches.

The Demon King Order harvests lives from all manners of living beings.

Within this darkness full of despair,
A single person escaped from space-time, returned to before the world collapsed, determined to change the fate of the past.

But as time pass, he gradually finds out that the Apocalypse isn’t quite as simple as he thinks…

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.