What do you think is the classic foreshadowing of One Piece?

If only the name appears, Gibel should be the second Seven Seas. At that time, when Joseph introduced the background of the dragon to Luffy and Shan Zhi, he mentioned that Gibel, the "Seven Wuhai", was once the leader of the dragon. So Gibel must be the decisive figure in the back, but it was not so obvious in the early stage.