Holy Diver

Holy Diver (Japanese: ホーリー・ダイヴァー, Hepburn: Hōrī Daivā) is a 1989 Japanese video game for the Nintendo Famicom home console. It was developed and published by Irem.

It is the 666th year for the world of magic, and the Crimson Kingdom is facing destruction at the hands of The Black Slayer, Demon King of the Underground Dark Empire. Realizing that his days are numbered, the 16th Crimson Emperor, Ronnie IV, decides to entrust his two infant sons, Randy and Zakk, to his faithful servant, Ozzy. With Slayer's forces closing in, Ozzy, Randy and Zakk escape to another dimension, with the hope of eventually bringing light back into the world.

Over the following 17 years, Randy, Zakk, and Ozzy devote and train themselves to the cause of Magic Justice, becoming wizard kings. Meanwhile, Black Slayer has increased his empire over the countryside, making his interdimensional forces even stronger. In order to defeat Black Slayer and his army, Randy must retrieve the Five Crimson Emblem Seals. Making matters worse, Randy now must wage his war against Black Slayer alone, for Zakk suddenly goes missing and Ozzy passes away.

Source: Wikipedia