Eternal life begins with saving my clan - Chapter 300: Conquering the state in one night:

Makoto found himself transmigrated into the world of Naruto, but there was one small problem.He was a mere lackey, someone who didn’t even get a single line in the original story.But fate had a twist in store for him.Makoto awakened a Chat Group, where every member was a former powerhouse of Hidden Leaf Village. What’s more, with thier consent, he can inherit their bloodline, combat experience, ninjutsu, chakra, and so much more!How will the story of Naruto change with the inclusion of Makoto? How will the group members react upon discovering the current state of the Hidden Leaf Village and the fate of their loved ones?

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

William and his college class are ripped from Earth and thrown into Aethel, a world on the brink of collapse. Everyone gains incredible magical powers – except William. Mocked and underestimated, he’s an outcast among heroes. But William has a secret: an SSS-ranked skill that lets him travel to Aethel’s past. Learning lost magic from ancient masters, he’ll surpass his classmates and become the true savior Aethel needs. But can he overcome the dangers of the past and present to forge his own destiny? While others studied about the first mage, William could go back in time and see the first mage himself! While others dreamed of seeing a dragon, William could go back in time, hatch a legendary dragon egg and turn it into his puppy. While others used common materials to craft their items, William could go back in time and mine materials that weren’t find anywhere in Aethel anymore. Is it unfair? Perhaps, but William was not the type of person to not use the powers the universe gave him.