I Became the First Prince: Legend of Sword's Song

Synopsis

Reborn as a sword, I lived for several hundred years, spending my entire existence looking after everyone. Then, out of nowhere, I took over the body of a fifteen-year-old uncouth first prince. "Do you have any idea how many I've raised?" The great knight once called the Undefeated, the Dragon Slayer who brought down the Mad Dragon, the Mercenary King, and more... I raised every single one of them. The Magic Sword Gruhorn possessed the body of the uncouth first prince... And has begun to write a new legend. (Source: Kakao Entertainment, translated)