Herman was once known as the famous pirate Black. He collected a huge amount of treasure, which he hid inside a series of caves in the peninsula near the Great Arc. He retired after a fateful confrontation with the Abyss Lord Forneus, who took away his youth, turning him into a old geezer. Many people now go to the Great Arc in search of his treasure.
Herman can be recruited in the Great Arc, if the player has already found his way into Vanguard's control room. Since the dolphin statue needed to operate the room is in Herman's possession, he will join and lead the group into the cave where he hid it. After Vanguard is fully operational, Herman leads the group into Limit Island, where the lobsters there inform the location of the Sea Palace, where one of the Abyss gates is located.
Herman is also needed in the group to trigger the Maximus chase quest.
Herman is a really bad character when you get him, as he only has 4 LP, is very slow and misses a lot. If you take him into the battle with Forneus and defeat the Abyss Lord, Herman will recover his youth and change his name back to Black. After that he becomes a powerful character, specializing in axes and staves, as well as wind magic.