MTL - Studying Science in the Alternate World - Chapter 20 hang up practice

Baek Yigang is a son of the Baek Clan, one of the seven great clans of Zhongyuan. Afflicted with the Taiyin Qi Blockage, he is cursed with a shortened lifespan and the inability to collect internal energy. He had been peacefully spending the rest of his days indoors when he was ambushed by a group of masked people. During the ambush, he lost his servant who was like a sister to him. Chased by the attackers, Baek Yigang escaped through a secret underground path. When he came across a blocked path, he decided he’d at least die fighting and picked up a rusted sword that was stuck in the ground…

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

Kazura was selected as the winner on a lottery that he bought on a whim and received ¥4,000,000,000 (4 billion yen).

Crying blood and tears, she pledged a poisonous vow. The gods did not fail her. She was sent back to a decade ago. The legitimate daughter of Jiang family returned from hell.