Great Demon King - Chapter 15: I’m rich, I’m rich

The Soaring Dragon Continent is a world of summons, you can only become strong if you become a summoner! Yue Yang, an average high school boy, was suddenly transported into this world. When he woke up, he was greeted with a lot of worried faces and found out that he had assumed another person’s identity. Turns out he’s the good-for-nothing third son of the Yue Family, who had just recently drowned himself because of a failed engagement. Unlike the third son of the Yue Family who was useless in summoning, Yue Yang succeeded in making a contract with a summoning grimoire on his first try, even when the other guy failed for the past fifteen years. Others would have a headache making contracts with beasts afterwards, but countless beasts tried to gain favour with Yue Yang instead, acting like a good kid before him.

What if life could be repeated?

But he became the clan uncle who was once called a lunatic?

Alas, wearing open-crotch pants in front of me, crawling on the ground, is it my two-year-old self?

I originally wanted to give my former self more New Year’s money, but I never thought that I would go from a braised pork stall to a food giant, from a small factory to an industrial empire.

- Description from novelbuddy

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

For the wine to be drunk on her wedding night to actually have been a cup of poison and for the one to poison her to be her husband, who would believe it?