Shikkaku Mon no Saikyou Kenja~ Sekai Saikyou no Kenja ga Sarani Tsuyoku Naru Tameni Tenseishimashita~ - Chapter 248: Strongest Sage, Sells Materials

A novel revolving around being transported to another world with an op system. The mc spends his day chasing skirts and doing missions to level up. A standard journey to the top with lots of girls from various animes and games with a twist of that gaming feel (hunting mobs, doing missions).

- Description from novelupdates

Only a pure maiden can have a privilege to make contract with a spirit.

In Areishia Acadamy, maidens from noble family were gathered there, giving them an elite education to become a spirit contractor. A boy Kamito, by accident he peeped on a girl, Clair, who was taking a bath, and he even made a contract with spirit that she wanted.

Kamito was actually an irregular male spirit contractor, which should not exist.

After sleeping for over two thousand years, she woke up, only to find she had lost everything and was even going to be sold at an auction by her father.On her way to escape, she met him by chance. He was so handsome and adorable, like a cute little dog. So they got married in a flash.Later, she accidentally met the first interstellar commander whose mask had fallen off. Rumor has it that anyone who sees his true face will die. She trembled with fear, “What a coincidence! You look exactly like my husband!” He said, “I am your husband.”From then on, he clung to her every day, wanting to have a child. She felt regretful: He looks like a wolf now! She misses the little puppy she used to have so much...

Through a chaotic world rife with war, where demons roamed freely, he found himself in the body of the patriarch of the Luo family, whose life was nearing its end, with one foot already in the grave.Just after arriving, he was about to die?What kind of mortal suffering was this?Just as Luo Changfeng felt bewildered and on the brink of despair, he discovered that he could actually consume the vital energy of the Luo Family members to increase his attributes.A little tap, and his lifespan grew.A little tap, and his cultivation soared.A little tap, and his cultivation technique reached perfection.Thus, Luo Changfeng embarked on a path of empowering his family, continually drawing upon their vitality to strengthen himself.