Kenja no Mago

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 Merlins teachings earning him some shocking power however when he became 15 his grandfather Merlin said I forgot to teach him common sense
An abnormal boys unconventional otherworld fantasy life starts here