Luckily, Eiichiro Oda gave some details at Jump Festa 2018 and the series' main villain has a tie to a formerly major character, Whitebeard.
With a message during the One Piece presentation at Jump Festa 2018, Eiichiro Oda dropped some major hints about the next stage of the series, the "Wano" arc, "One Piece will finally enter Wano next year!!" Oda goes on to apologize about the arc's delay as "[he] thought OP would be able to enter Wano in 2017."
Here is my full translation for Oda's message in Jump Festa 2018 today😍 pic.twitter.com/zJt4EYFhCP— sandman (@sandman_AP) December 17, 2017
But Oda made up for this delay with some major information, "I'll introduce one of the legends which lurks in the One Piece world. The greatest enemy ever for Straw Hats will hinder their way. Perhaps it will be related to Whitebeard. Oops, it seems I'm being too talkative. Can you believe Marineford Summit War will look 'cute' compared to that?"
Not only will the Straw Hats face the greatest enemy they've ever come across in the next arc, which will seem insane after dealing with Big Mom, but that new enemy may be related to Whitebeard. A matter of how they relate to Whitebeard is still up in the air as Oda's coy response even indicates that maybe he means that the events of the story will be related to Whitebeard in some way, rather than the villain themself.
Along with a major villain tease, the fact that Oda is planning a battle larger in scope than Marineford will definitely have fans eagerly awaiting Wano. Surely fans can't wait to see how this all shakes out.
Eiichiro Oda's One Piece first began serialization in Shueisha's Weekly Shonen Jump in 1997. It has been collected into 87 volumes, with a few chapters yet to be included. It has been a critical and commercial success worldwide with many of the volumes breaking printing records in Japan. The manga has even set a Guinness World Record for the most copies published for the same comic book by a single author, and is the best selling manga series worldwide with 430 million copies sold worldwide.
One Piece is currently in the middle of the "Whole Cake Island" arc and is now streaming on Crunchyroll and FunimationNOW.