In The Supreme Fantasy World, Back In Time And Do Whatever You Want! - Chapter 79 - . Serena Will Do What He Did To Her!

Once upon a time, the Land of Promise thrived under the cycle of the four seasons change. Until a vengeful enchantress cursed the land, and divided it into four realms each with a ruler to bear its burden.The people suffered for years under the endless heat in the Summerlands, the bitter cold in the Winterlands, the never changing bloom in the Springlands and the constant fall in the Autumlands.A prophecy whispers of a marriage between a king and queen that will release the land from its curse and unite it under a single kingdom.Princess Caroline is forced to marry the Summer King, will she be able to fight for a peace amidst a court full of power hungry nobles and will she succumb to a burning love in the arms of a fiery warlord?

Qin Xiaobai transmigrated into a husky.
And his master turned out to be a goddess-level live broadcast.
Reporter: “Miss Su, you are now the first sister of Douyu. What’s the secret of your success, is it your good looks or hard work?”
Su Wanqing thought for a long time, then pointed to Erha beside her and replied, “It doesn’t seem to be the case. The main credit for my current achievements is that my Erha is so outstanding! Sometimes I even doubt that my Erha is the protagonist. …”

- Description from novelbuddy

The MC entered the body of the An family eldest son, An Ziran, an arrogant 16 years old boy who weighed 78 kg (~171-172 lbs), who only knew how to eat, play and sleep. Seeing his current body, An Ziran decided his first priority was to LOSE WEIGHT!

Three days later after he became An Ziran, An Ziran’s father and his biological mother died, which meant as the eldest son he had to take over the family business.

Beside his legitimate first wife, An Ziran’s father also married 3 others women, who all wanted to take over the An family fortune but only the eldest son could be able to touch it, therefore they have to depend on An Ziran in order to live a comfortable live.

An Ziran’s father also had an older brother who is always planning to steal the An family fortune. The elder brother of An Ziran’s father and the woman he married had powerful connections. In order to save the An family fortune, An Ziran has to find a golden thigh to cling on. The butler told An Ziran that there is an engagement between the An family and an influential family. Therefore he takes his sister to that family house to make a connection.

However, during their journey, An Ziran’s younger sister overheard that the son of that family is UGLY, so as a beautiful and spoiled young lady coming from a rich household, she didn’t want to marry him and decided to run away. Without any other choice, An Ziran had to take his sister’s​ place and marry that man, who told him that he would let him go soon, but lied.

- Description from Novelupdates

In a monstrous post-apocalyptic setting, this is a story of how a lowly Inventor, Lance, conquered a nation governed by immoral group of Scientists called The Corporation. He grew and climbed up to the highest rank possible as a Scientist with his inventions and side businesses. Eventually, he became a weapons inventor, building weapons to two opposing sides. In doing so, Lance always crossed a dilemma. How could a nobody topple the most powerful government? How could one overcome circumstances beyond his grasp, especially in a world filled with monstrous mutations called the Abominants?