UNMEI: Pantheon's Game - Chapter 83: Shell Town

In the Year 350 of the Anping Dynasty, humans were faced with a huge crisis. Earth was invaded by monsters from another dimension. Fortunately, Su Yu awoke a power where he possessed a scripture that allowed him to contain everything in existence. With that power, he was able to face the coming apocalypse.

Accidentally reborn as the son of the distant cousin of the Squib, the mother of Harry Potter’s friend Ron, and lived in this world as the second generation of Squib for eleven years.

He originally planned to be an accountant like his father in the future, but he didn’t expect fate to play a joke on him, and he didn’t know the slightest bit of magic, but he received the exact same envelope as his sister on his eleventh birthday.

Due to the expectations of his parents, he reluctantly accepted the reality, but inadvertently discovered another secret…

- Description from novelbuddy

“Obtaining the topmost degree of talent in sword arts in the world requires giving up 72 years of lifespan, which leaves you with only five more years of your life. At the same time, you will never be able to feel love, kinship, and friendship, and you’ll end up leading a lonely life until your death, unable to procreate, or to have any descendants.“From now onwards, everything related to happiness in the human world shall no longer be of your concern. Are you willing to accept this?”“Hahahaha, I’m already alone bereft of all support, my hopes dashed to pieces, shouldering only absolutely irreconcilable grudge and hatred, why would I disagree? Why would I not want it? I couldn’t ask for anything better!!”His sword sweeps across the Divine Continent for seven days and nights, moving 90,000 miles through the starry skies, unhindered.He slays saints and buddhas in Heaven, slaughters demons and devils in Hell, sweeping away all the grievances in his heart.

Ajax used to coast through life before his parents died, after that he focused hard to try get his life back on track but that wasn't really happening and it all ended the day he got mugged. Given a second chance at life he now looks to become someone who matters and is willing to work hard from the beginning to make that happen.