Arcus Adventure

There's a young man that just lost his parents a few days ago, he goes to nearby cave to escape from all of this. there he found a mysterious thunder, the thunder went inside his body and he fainted

When he woke up he was in a different place,an old geezer told him that if he want to back to earth he will have to defeat the 4 GrandGod, From there he set his new Adventure to defeat the 4GrandGod