The Undercover Heir is Actually Tycoon's Secret Girlfriend - Chapter 90

Xia Yan passed through to the world of Bleach and became an eleven-year-old boy. He was rescued by Renji and Rukia in the Seireitei, and he was studying at Shin’ō Academy, and he was a student of the same class.
He is a top student of the Shin’ō Academy, and he is vying for strength by various teams. In the end, he has entered the first team of secret mobile maneuvers.
He will use punishment to kill every person who tries to threaten the martyrdom and protect his loved one.

- Description from Novelupdates

He’s the Wolf King on the battlefield, one that mastered peerless martial arts and the sophisticated art of medicine. He originally wanted to just live a peaceful life, but his wife who’s a CEO thought he’s a loser and wanted a divorce. The cold war between husband and wife began.

Translator : Noodletown Translated Editor : Noodletown Translated

In a peculiar twist of fate, Lee Taeok, found himself in an extraordinary predicament. Little did he know that his scathing critique of a popular novel, ridiculing its blatant naivety and overly innocent take on romance, would set in motion a perplexing chain of events, ultimately leading to his unexpected rebirth as the delinquent character, Baek Taeyang, from the very same novel.“You should have taken better care of your girlfriend.”In the world of the Academy Sweet Love Diary novel, Baek Taeyang is destined to “rescue” the heroines.

One day, I woke up only find out that I’d become a Demon Lord, an individual responsible for protecting a dungeon. The world I’d been spirited away to was one filled with violence. Gigantic monsters wandered through it and competed with each other each and every day for the right to survive. I had no choice but to strengthen my dungeon’s defenses in hopes of living another day—or at least that was what I’d thought. For some odd reason, I instead ended up spending my days in relaxation and bliss.