The beginning after the end

"King Grey is a remarkable ruler with a prosperous reign, and yet. . .opulence and success cannot bury emptiness and solitude. His time as king, however, comes to an abrupt end, and he reincarnates as Arthur Leywin--a baby born in a world of magic and monsters. Equipped with memories of his previous life and the desire to protect the newfound warmth surrounding him, Art begins his journey of becoming a strong warrior once again. Sword training, mana core formation, magic studies--Art does it all in order to be as powerful as can be! But will it be enough to repel the dangerous forces that threaten his second chance at life?"--Provided by publisher.