One Piece: New Order - Chapter 72: Devil Fruit and Haki

When an S-class elite assassin-raised captain of a special ops suicide squad comes home from a high-stakes Africa mission, he finds himself offered something that could potentially set him up for life- a curious assignment that he could use to finally exit his days of war and slaughter.

For a long time, Malin always felt that Fate had been quite generous to him. Although he had to face that life-threatening job every day, as long as he had the lovely Leopard Girl cooking delicious food for him daily, and as long as there was meat to eat and cats to stroke, life wasn't too unbearable. Working a bit harder and facing some difficulties on the job weren't really an issue for a man.Moreover, being able to live two lives meant one shouldn't have too high demands, right, Mr. Different-Kind?Having said that, and without waiting for an answer, the young man snapped his fingers, and the white flame on his fingertip lit the tobacco in his other hand, then he flicked it towards the non-human entity on the stake.Welcome to Abield, to witness the last splendor of the steampunk era.And the madness.

The world that nurtured the civilization which reached the pinnacle of magic was on the verge of destruction.
The last survivor transmigrated to the past, when the magic civilization started growing, as countless mages were still fumbling their ways through the thorny paths of magic knowledge.
He, who came from the end of the magic era, aim to reach the pinnacle of magic.

- Description from Novelupdates

When I died I meet with this being who offered me a new chance at life, to actually become someone important and I agreed and was reborn as none other as the First Man.But to think that everything that I ever knew was nothing more than a lie, what am I going to do to survive in such a world?