Leviathan of the Covenant - Volume 4, Prologue

The eldest daughter of the Li family is beautiful and sassy, ​​she took space materials to flee famine, and after going through many difficulties in war, disease and epidemic, she united with her family to regain the glory and harvested a beautiful boy.

- Description from novelbuddy

Once she transmigrated over, Li Haitang, an elite female doctor from the big city, is demoted to a pitiful little cabbage whose parents have both died. She is surrounded by extreme jackals, wolves, tigers and panthers family and relatives. What? She is sold to a half-dead body that is going to be buried in the ground. Has she been sold to an old man with a heavy taste? The only way to escape from the arranged marriage is to pack a bundle wrapped in a cloth! Who would have thought that on the way to the wedding, she meets a wild man who is feared by everyone in the village? The wild man has three treasures, he is hardworking, spoils his wife and has good stamina! His pectoral muscles, abs and mermaid’s line are all there.

- Description from Novelupdates

Lieutenant Jack Fritz is a self centered American man of German descent. He like many joined the United States Navy in hopes of getting an easy life and easy money. In fact getting money and taking it easy is all he has ever really wished for in life.However life seems to have other plans in-store for Jack as he suddenly finds himself at the beginning of World War 3. Though his fight does not last for long as he is suddenly blown to bits by a missile and sent into the afterlife, but instead of going to heaven Jack is dragged to another place where he is given another chance at life by some fiery demon for a price.Having been given no other chance Jack does as the demon says and earns himself life again. Though he doesn't return to his original world, but a medieval one. With no guidance and no higher purpose given to him he simply decides to do the best that he can within this new world of his. This time he will for sure earn that perfect life of his and possibly a lot more.But little does Jack know his fate is not his own and there are many sinister things in-store for him. Also the world he finds himself in is not a safe or simple medieval world, but one beset by dangers from all sides that are already little by little driving humanity towards its extinction.