Starting on May 8, Thanos from Avengers: Infinity War is coming to Fortnite in a limited-time crossover event where you could wield the Infinity Gauntlet. The event plays out like normal, the difference being the Infinity Gauntlet with all the Infinity Stones. Find it in the map and it’s yours. The crossover is available for free across all platforms, but there are no further details such as when it ends at this time. According to Entertainment Weekly, the whole endeavor came about due to the movie's directors, Joe and Anthony Russo, being fans of the game.
"Over the past few months, while we were editing Infinity War, we'd take breaks to on and get in a few games," said Joe Russo. "And then we started thinking, 'How cool would it be to have some kind of Avengers-Fortnite mashup."