Wise Man's Grandchild(賢者の孫)

A young man who had surely died in an accident, was reborn in another world as a baby! After that, he was picked up by the patriot hero "Sage" Merlin Wolford and was given the name Shin. He was raised as a grandson by Merlin and soaked up Merlin's teachings, earning him some shocking powers; however, when he became 15, his grandfather Merlin said, "I forgot to teach him common sense!" An "abnormal" boy's unconventional other world fantasy life starts here!