I really think the One Piece is a giant bowl/bottle of sake which probably lines up with Luffy/Rogers dream to make the entire world their brothers/nakama and have a giant party or some bs like that. I think Luffy, Blackbeard, Shanks and Buggy will all show up at laugh tale at the same time, Luffy vs Buggy, Blackbeard vs Shanks, Blackbeard will kill Shanks which will basically halt the fight between Luffy and Buggy who will then face off against BB.