Mark of the Fool - Chapter 840: The Final Trial

Zaiyila thought she had suffered enough—betrayed by her own mother and sold into marriage with a wealthy, aging man. But on the night of her pre-wedding ceremony, everything takes a dark and unexpected turn. A swarm of deadly snakes descends upon the gathering, killing her groom-to-be and throwing the hall into chaos. Fear spreads as the people recognize the serpents as the servants of the enigmatic and terrifying Snake King, Everett.When Everett himself arrives—a striking, horned man of unmatched beauty and power—Zaiyila finds herself drawn to him in ways she cannot explain. Despite the fear he inspires in others, she feels an unshakable connection to him, one that transcends the realm of logic. The moment she defies the fearful kneeling of the crowd, she unknowingly seals her fate.Taken into Everett’s domain, Zaiyila is forced to confront not only the dangerous, supernatural world she’s been thrust into but also the awakening desires she cannot deny. As she unravels the truth about her past and her connection to the Snake King, she must decide—will she resist the pull of destiny, or will she embrace the darkness and passion that Everett offers?A tale of betrayal, power, and an irresistible bond, Bride of the Serpent King explores the fine line between fear and desire, fate and choice.---

Three years ago, the animals and plants on Earth underwent crazy and unexplainable changes that included transformations, reversions, and the addition of otherworldly species. And it was the start of a brand-new type of profession in the new generation of humanity – Monster Trainers, people who specialized in taming monsters.

On his 18th birthday, the protagonist of the story, Gao Peng, suddenly received the ability of being able to see the attribute data frame of monsters. With his ability, he aspired to become the strongest monster trainer that ever lived while looking for a method to revive his parents!

- Description from Novelupdates

Jacob Steve, an Old Man, died at 116 after living a whole life.

But Jacob always had a dark side, which he always suppressed and hid from others.
However, in the later years of his life, when death was inevitable, he understood there wasn't any point in having wealth, knowledge, or desires if you couldn't have a life to enjoy them.

He became obsessed with fabled immortality and devoted his reaming life to extending his fleeting lifespan, but just like any other failed.

However, he mysteriously got another chance at life and found a way that led to fabled immortality.
But he was also forewarned that the way led to it was filled with blood and darkness!

In the end, Jacob chose it anyway with no way of going back, and it was also the start of his suffering and his icky, brutal journey toward the 'Immortality' he wanted so badly!

Another entry in what you can call the Proto Harem Series: the books written before the Harem Series that take place in the same world.

It’s about a swordswoman whose student is captured, so she goes to rescue her.