Mugen no Majutsu Shi Maryoku Nashi de Heimin no Ko to Hakugai Sareta Ore. Jitsuha Mugen no Maryoku Mochi

Resto, a boy who was reincarnated with unlimited magical power. For some reason, he pretends to have no magic power and spends his days enduring persecution, but... But his life changes forever when he saves the lives of Viola and Primula, the daughters of a court magician! 'To have as many children as possible of his blood born to the Marquise Rosemary... Recognized as a gifted magician and his sisters' son-in-law, Resto spends his days training for the entrance exam to the Royal Academy as a live-in student... His talent is honed as he defeats unorthodox demons and develops unorthodox magic, accomplishing feats no one could have predicted. With the strongest magic power, he takes everything into his own hands - a tale of infinite success begins! Winner of the 9th Kakuyom Web Novel Contest, Otherworldly Fantasy Category Special Award & CW Manga Award.