No Fatigue: 24-jikan Tatakaeru Otoko no Tenseitan

After being killed while protecting a female high school student from a slasher, Kagi Tomonori is revived by a goddess who allows him to be reborn in another world, on the condition that he use his newfound power to stop the slasher, Kizagi Tooru, who has also been given a second life by an evil god. Tomonori is reborn as Edgar, the fourth son of a viscount family, with the ability to remain physically and mentally active for 24 hours without fatigue. He uses this power from infancy, training for 46 hours as a newborn to develop skills at an accelerated rate. Later, when Edgar's father, a fortress commander, is attacked by an enemy group known as 'Black Wolf's Fang,' Edgar encounters a foe whose traits mirror those of his former enemy, the slasher.