One Piece: The Soul Purchasing Pirate - Chapter 13

A naturally timid engineering student found himself transported to France before the grand revolution, only to become the older brother of the future Emperor Napoleon for some inexplicable reason. Now, he faced a crucial decision: would he seize this opportunity to create his own remarkable destiny or merely cling to this lifeline and drift along?

Zhou Yu, a reclusive otaku, who did not like to go out of his house, was one day forced out of his house by a series of unexpected events.

- Description from Novelupdates

A war veteran and an anime fan as well, he got into anime by watching it with his grandson after his retirement, his grandson loved pokemon and so did he also came to like this world of pokemon where people didn't kill each other and people used to have fun with there pokemon, after watching Pokemon with his grandson and playing with him all day he got back his childhood which he could never experience due to the cruel war, and as of now our MC has turned 82 years old he was very satisfied with his life with no regrets and waiting for death to take him away but will death be is end or will it start a new beginning, a new legend.

After the ‘100-Year War’ between the Necromancers and Priests, an all-time genius who’ll shake the power structure was born. “Am I a rare case or something? Do I have talent?” A potential beyond all imagination. He obtained his father’s undead army and entered the great Necromancer school of Kizen that divided the continent. Geniuses are geniuses, even when gathered among the elites. The research community was flipped on its head by the appearance of a new case. Professors wouldn’t leave him be alone, wanting to make him study directly under them. Officials from all over the kingdom and heads of organizations fidgeted over whether to scout him. “Professor! When can I make a Lich?” “Gimme a break. How talented are you? You’re crossing the line, honestly.” A genius among geniuses had appeared.