Big Mom has been giving the Straw Hat crew a ton of trouble ever since they came to Whole Cake Island in order to get Sanji back, and while the anime has definitely shown instances of her fearsome power it had yet to demonstrate just how evil Big Mom could be.
In episode 822 of the anime, we finally get to hear Big Mom's full plan for Sanji's wedding. It's one thing to hear it from Pudding, but it's an entirely different beast to hear how Big Mom gleefully plots a massacre.
Detailing her plan for Sanji's wedding, while dangling the defeated Brook from a string and flailing him around, she's far too happy to be this maniacal. The plan was for Pudding to attack Sanji when they were getting ready to recite their vows. He would lift her veil, and see her third eye. Catching him off-guard, Pudding would shoot Sanji in the head (or between the eyebrows as Big Mom says).
Following the shock of this, the Vinsmokes would indeed retaliate but when they do they'd see the guns of the Charlotte family pointing back at them, killing them all. Big Mom takes such a joy in reveling in her plans and adds and etra layer of fearsomeness we have yet to see.
The one of her voice is definitely darker in this moment, as the rest of the arc she seems to be a bit more playful when contending with others like Brook. This is also in reference to her Roulette of Death, which steals the life of any who spins it since she rigs the "game" to punish in high numbers.
Big Mom has been a big presence, and a terrifying one, but this episode made her all the more bone chilling.
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.
Eiichiro Oda also revealed some upcoming news for One Piece's future at Jump Festa 2018. Not only will the manga see Wano sooner rather than later, the next villain of the series is "one of the legends which lurks in the One Piece world. The greatest enemy ever for Straw Hats will hinder their way...Can you believe Marineford Summit War will look 'cute' compared to that?"
One Piece is currently in the middle of the "Whole Cake Island" arc and is now streaming on Crunchyroll and FunimationNOW.