Academy’s Genius Swordsman

A brief description of the manhwa Academy’s Genius Swordsman:

Ronan, who had always squandered and lived a life filled with regrets, is given a second chance when his life was about to end in vain.

And that chance is when he was sent back to his childhood ten years ago!

Ronan makes up his mind to live a new life for the sake of many people who have sacrificed themselves for him.