For this Fortnite challenge, Slone will ask you to find one of the last alien weapons to appear on the map, the Grab-Itron.
All you need to do is acquire and equip it, meaning this challenge is actually one of the more simple ones out there.
Here's where you'll need to look for the Grab-Itron.
The Grab-Itron has the same effect as the tractor beams of saucers you can findall over the island. It allows you to attract items in front of you.
For example, you can grab a truck, take it with you and then -- this is where it gets interesting - throw it at your opponent of choice.
The damage you will inflict depends on the size of the object, its composition and its throw speed.
That's not all - the Grab-Itron can also block damage from the front, until the object you are holding is destroyed.
Finally, you can also try to catch explosives in mid-air and send them back to where they came. Nice!
As for the where to find a Grab-Itron -- simply look in chests, on Saucers, or even in the Mothership.
If you want to complete the challenge in record time, a good tip would be to land on one of the Saucers you can see on your minimap at the start of the game.