Black Manta Fortnite is now a useable outfit ahead of the Atlantis event launch. While the specific date has yet to be revealed to the world, we could see it sometime over the next few weeks. Aquaman was teased before the launch of Chapter 2 Season 3 as the replacement for Deadpool, and that turned out correctly, so the datamined information about the Atlantis landing spot will likely be true as well.
Black Manta Fortnite: Aquaman Villain Arrives Ahead of Atlantis Launch
During the recent film where Jason Momoa plays the hero, Black Manta is recruited by Ocean Master to hunt down Aquaman. Manta is depicted as a treasure-seeking pirate that lost his father in a fight with Aquaman. He's seeking revenge against Aquaman and plays the perfect villain.
The map is slowly losing water level, and the next scheduled level drop is July 18. This should provide small map changes until the actual release of Atlantis. Most likely, we'll see an in-game cinematic of sorts with the two characters fighting one another.