Over the course of Black Clover, Asta has collected three very powerful swords: Demon-Slayer, Demon-Dweller, and, most recently, Demon-Destroyer. Each of these weapons can be exploited in highly specific ways, although it's not always obvious to Asta when he uses them for the first time. Although he receives the Demon-Slayer and Demon-Dweller swords early on in the series, he only obtains Demon-Destroyer in Episode 100.
Source：https://www.cbr.com/black-clover-asta-demon-destroyer-sword-explained/
