Oh, Blackbeard beat Ace and Ace is in Impel Down, the submarine where they imprision all the DF users. Luffy might not the first time, just because Luffy doesnt think, he just fights. But if Luffy is given two chances to fight Blackbeard, Im sure he will come up with something, cause remember he didnt come up with the Gears until he fought Akoji and was partly frozen |