MTL - Mermaid Effect - Chapter 35

She, a renowned assassin of the 21st century, actually crossed over to become Su Manor’s most useless good-for-nothing Fourth Miss.

When he wakes up, Su Changkong has traveled to a world where troops are chaotic and demons are rampant, and his martial arts qualifications are mediocre, but Su Changkong found that as long as his [lifespan] increases, his talent and potential can be [infinitely] improved!

Wu Qin Xi: imitating tigers, deer, bears, apes, birds and other animals.

Turtle Breath True Dinggong: Imitation Qigong, like a thousand-year-old tortoise breathing, breathing, breathing and closing for a long time, prolonging life!

Celestial silkworm magic: nine transformations of the silkworm, breaking the cocoon into a butterfly, rejuvenating the old and rejuvenating, opening the door of life and death, every transformation is a rebirth!

Cultivation of health boxing, practice the Qi of longevity! There are many corpses on the road of longevity, and Su Changkong has embarked on a longevity martial arts where heaven and earth are destroyed but I am immortal!

- Description from novelbuddy

The male student, Fukai Nagamasa, ignores his studies for college entrance exams in favor of following the path to chuunibyou. As he fainted during night cramming session before the exams, he realized that he was transported to a parallel world as a feudal lord in the Sengoku Era. Not to mention that suddenly, he was marrying the sixth Demon King, Oda Nobunaga’s little sister, the one who was purported to be an unrivaled beauty?