Reincarnation of Nikola Tesla in another world - Chapter 23: regret - always

Lucan Ironfist came from a noble family, but he wasn't the eldest son. When his brother became the head of the family and he turned 18, Lucan would become a commoner. A strange rule, but that's how it was. So Lucan began to think of a way to live a peaceful life.As he was considering this, his mother arranged for him to become a priest in another city. A priest didn't have to worry about food or housing, and all he had to do was watch over the temple and the statue.It was easy work, so he agreed and arrived at the city. One day, as he was watching over the temple and the statue, a poor-looking girl came to pray. When she prayed to God, light gathered around her body.Lucan was surprised and suddenly remembered the plot of a certain game. Originally, Lucan was from Earth and had traveled to this fantasy world. When he was on Earth, he played a game with a plot where a merchant family's illegitimate daughter, bullied by her family, awakened the power of a saint.Lucan decided to keep this secret and train the saint so that in the future, he could have an easy life and save himself from any crises.

He became a teacher at the best magic academy in the empire.
….For being mistaken for someone else.

This novel is also known as A Stay-at-home Dad's Restaurant In An Alternate World

There is a very strange restaurant in the City of Sin.

Elves and dwarves must share a table, orcs are strangely well behaved, dragons are only welcomed on the small square in front of the restaurant, and the demons must bring their own stool.

This strange restaurant with their strange rules continuous to attract a long line of customers.

“This place serves the best food! The chef of this restaurant is a genius!” Some of the guests in the restaurant left glowing reviews. But these guests have a word of warning for other guests, “No matter what you do, never, never attempt to kidnap the boss or try to ‘eat and run’. You will die.”

A cute little girl stood near the door, and demanded in her tiny voice, “You have eaten the food, now pay up, or I will beat you to death.” The five-meter tall dragon suddenly felt a chill running up its spine.

- Description from novelupdates

There are three realms in the multi verse; The Cosmic, the Mortal and the Nether realm.

Hal grew up in the mortal realm with no idea whatsoever of who his parents were.

His love for relics, adventure and the occasional danger would aid him in finding a genie's lamp.

Rubbing a genie's lamp should grant three wishes, but Hal is struck by lightening instead and eventually arrives in the Cosmic realm with a large book in his mind space titled; The Primordial Cosmic Grimiore, that apparently holds all knowledge for a perpetual reign.

And so Hal's journey begins in a little city called Salmon city, in the body of a 17 year old boy also named Hal but was sold into slavery by his own father.

Hal finds out who his mother (prior to reincarnation) whose bloodline now flows unmixed in his new body is....

Join Hal as he battles mortals, Dragons, phoenixes, Gods and many more together with his harem of Beauties for the complete subjugation of the three realms.