One of the new challenges in Fortnite Chapter 2 Season 8, and part of the Kakashi punchcard, is to hit players with Paper Bomb Kunai. This is a new item that was introduced to the game as part of the Naruto cross-over in the 18.40 update.
The Paper Bomb Kunai can drop as ground loot, or from chests, and will even drop as a Mythic item. That’s right, a Mythic item can just spawn as ground loot anywhere on the island.
If you don’t want to leave things to chance, you can also get them directly from Kakashi himself. Kakashi can be found just to the southwest of Lazy Lake, at a ring of stones near the lake itself. He will sell the Mythic Paper Bomb Kunai in exchange for 150 gold bars.
Once you have them, all you need to do is throw them at any enemy player that you see to finish up the challenge. You need to land three hits in total, and they will come in stacks of six. They don’t do a huge amount of damage, and you will need three successful hits to eliminate another player. You don’t need to land all the hits in a row, or even in the same match, to finish the challenge, however.