https://www.polygon.com/2018/6/14/17465298/fortnite-blockbuster-challenge-skin-the-visitor

Since the beginning of Fortnite’s fourth season, one mystery has kept the community coming back week after week trying to complete challenges: the Blockbuster skin.

For those of you who don’t remember the beginning of the season seven weeks ago, or were never quite up to speed to begin with, Blockbuster is the name of a challenge that appears in Fortnite for any player who buys the Season 4 Battle Pass. To complete the challenge, players had to complete the weekly Battle Pass challenges for seven of the 10 total weeks. At the end of the challenge — up until today — there was simply a silhouette on the traditional orange field that notes a legendary cosmetic item, leading players to believe that a legendary skin would be their reward.