https://www.gamespot.com/articles/fortnites-thanos-mode-ends-soon-following-latest-i/1100-6458877/

Update: End dates for limited-time modes in Fortnite usually aren't announced far in advance, but we now know when Infinity Gauntlet will come to a close. The mode, which provides players with the chance to play as Avengers: Infinity War's Thanos, ends on Tuesday, May 15. That makes this your last chance to dive in and get some seat time with Thanos. As noted below, he's now much easier to kill than when he first launched, although he remains extremely deadly. At this point, we don't know if Epic plans to ever re-introduce the mode, so you should jump in while you still can if you're interested. The original story follows.

Epic Games is updating Fortnite again to make changes to the limited-time Avengers: Infinity War mode, Infinity Gauntlet, which features the mega-powerful Thanos. Specifically, the update will change his attributes to make him more powerful, but also somewhat easier to kill.