Divine Luck: SSS-Rank Battle Maid Harem - Chapter 425: The Blight

In novels with a stud there is always a Senior Martial Brother like this:

In the early stages of the novel, his innate talent is high, his cultivation is good, his appearance is handsome, and he has an intelligent, cute younger Martial Sister as a fiancée.

In the middle stages of the novel, he is caught unprepared and defeated by a young disciple (the protagonist) in the sect who’s hardly remarkable at all. From then on, he falls from his godly altar and loses his brilliance. Even his young Martial Sister leaves him for someone else.

In the late stages of the novel, he continues to turn dark, going down the Demonic Path and becoming the major villainous boss. However, the protagonist still ruthlessly defeats him and his soul is eternally sealed.

Once Qin Mo opened his eyes, he discovered that he had become this Senior Martial Brother.

- Description from Novelupdates

Edmund Oakforest is expelled from his family after having a relationship with the king's daughter, who was already engaged to the navy commander. To avoid his execution, he is exiled to the unknown with 10 ships and 100 elite soldiers from the oakforest family, with other workers included. After days of travel, he finds himself in an unknown archipelago. Follow Edmund on his great explorations and the rise of a new empire.

The Spirit Network, known as【Deep Sea】 connected five continents as human civilization surged forward; yet, they were oblivious to the impending eternal night. With the Extraordinary Awakening, the edifice was about to collapse. Flesh is weak and pitiful, how could one ascend? The story began when Gu Shen, an ordinary youth, received a ruler that bore the truth. He peeled back the corner of this extraordinary world, becoming the largest moth among the thousands that dashed into the flames. If winter is coming, I will climb against the steps, overturn the thrones of kings, shatter the crowns of falsehood, destroy the scepters of injustice. I will become humanity's last, Bright Barrier.

Lyle Walt is a young noble boy and heir looking forward to the day he can inherit his family’s territory. Except around when he was 10 year old, his parents started neglecting him more and more in favour of his little sister, Celes.
On his fifteenth birthday, he is challenged to a duel by his sister to see who will inherit the household and horribly loses, being cast out of his family. Afterwards, he gets treated by the family groundskeepers and receives the family heirloom Gem from him that Lyle’s grandfather had entrusted to him. From there, he begins an aimless journey with his childhood friend and former fiancée, Novem, and the Gem-turned-Jewel that houses the memories, personalities, and Skills of seven of his ancestors.