This season, all Fortnite battle pass owners can access Deadpool's weekly challenges to unlock the Marvel superhero skin. One of the two challenges for the fourth week of the season is be to find Deadpool's Katanas. It looks like the superhero lost quite a bit in the Chapter 2 Season 2 lobby.
Once again, to retrieve Deadpool's weapons of choice you'll need to go to your computer to be informed of your mission. After, you'll have to go to your smelly HQ:
Once you have read the mission, all you have to do is find the famous katanas. The first one is on the wall near the computer in Deadpool HQ. For the second one, go to Maya Upgrade Room where the katana will be on the right, near the weapon case.
Completing this step will allow you to unlock a second challenge: deal damage to opponent’s structures. Once completed, you'll receive the weekly reward.