MTL - I Became the Pet of the Five Bosses - Chapter 88 precursor to collapse

A good-for-nothing man married a beautiful girl but was kicked off the bed on the wedding night. Furiously, he wrote a bill of divorce and ran away.
He was schemed a car accident in which he nearly lost his life. However, it turned out to be a blessing. He swallowed the soul that passed through the outer world, thus obtained superb medical skills and martial arts.
Later on, with the silver needles and invincible martial arts, he embarked on the road of counterattacks and was committed to his great dreams.

- Description from Novelupdates

Perhaps it is the choice of fate. As a senior otaku, Qian Lingfeng got the “steel shell system”. However, when he swept the world with the system, became a local rich man, made all kinds of beautiful women, opened a harem, and realized the ultimate fantasy of thousands of otaku, he found that things seemed far from simple!
When the end comes, biochemical zombies suddenly come down, fierce beasts are in power, bloodthirsty zerg roam to kill the world, and human lives are comparable to dirt. Where will weak human beings go in this world? Is humanity going to be extinct? Or … can an otaku save the fate of the human race?

- Description from Novelupdates

There was nothing left to lose in his life.He had lived as a hero. He had started at the bottom and worked his way up to the top, at the end he become the best, yet he had always been betrayed by those he had tried to protect.Humanity did not deserve his protection.When everything went out and he could no longer even hope to beg for his life, he could do nothing but look up at the blood-red sky among the corpses of demons and angels.He wished for one more chance, just one more chance.And when that chance was given to him, he swore that he would change everything. He would no longer be a hero to save people, but an anti-hero to save the world.Sacrificing hundreds of people to save an elf, poisoning hundreds of people to save a group of half-demons.He didn't care about any of that anymore, he would protect those he cared about and send everything else to hell.Not even the gods or goddesses could stop him.