MTL - Start the Source of Fire and Create a Mechanical Army - Chapter 380

Beings that create and control monsters and demons, beings that build and reign over malicious labyrinths, the chosen individuals to possess an overwhelming Unique Skill… They are the Demon Lords.

As the heir apparent of the Ye family, Ye Xuan went through fire and water for his family, but Ye Lang, who had just awakened his Divine Soul, usurped his place. In order to keep his position, Ye Xuan challenged Ye Lang to a Life-death Duel. With the broken Dantian, would he win this fight? The black ring his mother left brought him a great opportunity: Realm Hell Tower, where he met a mysterious lady, who told him to look for nine Daoist Laws to enhance his strength and gave him the Spirit Heaven Sword. Could Ye Xuan find all the Daoist Laws and become a powerful swordsman?

- Description from Novelupdates

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!