The Thanos patch has arrived. Go forth and dominate.
Update May 8, 2018: The patch is now live and Epic Games has detailed the limited time mode that includes Thanos and how the character behaves. Check out that and all the bug fixes and goodness over on the Epic Games blog.
Update May 7, 2018: The Avengers: Infinity War cross-over event arrives in Fortnite on May 8, 2018, and will give players the ability to find the Infinity Gauntlet and transform into Thanos. The “Infinity Gauntlet Limited Time Mash-up” mode in Fortnite Battle Royale will be identical to the standard hundred-player arena.