Last May, Epic Games teamed up with Marvel for a crossover event that brought the villainous Thanos and his all-powerful Infinity Gauntlet to Fortnite for a limited time event. Players could find and equip the gauntlet to transform into Thanos himself and wreak havoc on their opponents with overpowered punches and laser attacks.
The event was short-lived, but it may soon be returning. Data miners have been digging through the version 8.30 update, and they've discovered new kill and death feed messages that mention Thanos. Last year's event kicked off shortly after Avengers: Infinity War hit theaters, so it would make sense to bring it back around the same time that Avengers: Endgame begins its run later this month.
Source: SkinTrackerCom (via VG247)