Valerian, The Legendary - Chapter 245 - 245 Truth.

Xiao Yu, who was a student from modern Earth, accidentally transports to another world and becomes the lord of a territory. Facing an unfavorable situation, he vows to take back his family business, build his new territory, kill all of those who covet his wealth, and dominate the world!

- Description from Novelupdates

A man reincarnates in the body of a boy who suffered a tragedy, only to realize that he is in the world of My Hero Academia. What's even stranger is that his quirk seems to have the abilities of Nen and Haki.

Synopsis below:How did the Avatar universe change when a transmigrant appeared in an unknown village, long before the canonical events? And how are the two islands Kyoshi Island and Uzushiogakure no Sato (A village hidden in the maelstrom)?---Tags: AU, Before-canon, Post-canon, Violence, Death of major characters, Transmigration, Harem, Children, Incest, Romantic. Foul language.

In the land of the Xia Kingdom, every human being is born with what is known as a ‘resonance’, either to a specific element or a powerful, mythical beast. Unfortunately, Li Luo was born with an incredibly rare condition known as a blank resonance – as the name suggests, he doesn’t have one! Normally, this would be utterly crippling, but at least he has the advantage of being the young master of the mighty House Loulan, one of the five Great Houses of Xia. Unfortunately, his parents, the powerful masters of House Loulan, have gone missing for many years, and the other Great Houses are beginning to eye their holdings quite hungrily. For that matter, plenty are also eyeing his talented, beautiful childhood friend and fiancee Jiang Qing’e, who has been leading House Loulan in his parents’ stead! Li Luo would much rather keep a low profile and wants to call off the engagement – but Jiang Qing’e has flatly refused. What’s a ‘useless young master’ to do?