The Devil's Harem - Chapter 19 - Margaret, The Stalker

Waking up from a hangover, Wang Hao finds himself reborn in an alternate world. To his delight, he realizes that he has a system to help him in this new world. However, his system turns out to be a highly unconventional one. Instead of serving justice and winning the respect of other people, Wang Hao has to do all kinds of bad things in order to make use of the system. So, Wang Hao embarks on the journey to being cursed for good…

Lu Zhengfei personally killed Chen Qianqing with his abuse.

He cut off Chen Qianqing’s legs, and blinded his eyes, locking him up with chains in his house. Then, he watched with his eyes wide as he died. Injuries inflicted in the name of love would always end in a tragedy.

Did Lu Zhengfei regret it? Of course he did. And so, God gave him a chance to be reborn.

But this time, he found that he himself——became Chen Qianqing.

- Description from Novelupdates

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.

Xia Ning is betrayed by her boyfriend who wants to marry another girl from a rich and powerful family.