Tensei shichatta yo (Iya, Gomen)

As a result of a god's mistake, Shou prematurely dies. He is reborn in to another world as the oldest son, Will, of a highly distinguished noble family. One day, he crawls into his father's library and finds out that in this world magic exists. He tries to use magic, and to his astonishment, finds out that he has a cheat skill that increases his magical abilities and enables him to use all the elements! A fantasy about a former Japanese high-school genius who can wield magic like no other!

(Source: AlphaPolis)