So far, Asta’s Anti-Magic swords are very effective against elemental magic (water, air, earth, fire). His first sword can erase direct attack as well as repel it. His second sword (which is now in Licht’s hands) can absorb magic and use it as a long-range attack. But neither the two swords were seen to erase magic that can affect human’s body naturally like poison, Marx’s mushrooms or the Witch Queen’s blood magic. Asta is also rarely seen fighting against a non-elemental magic user.
This is the perfect time to test Asta’s third sword which is at this point is still not named. There is no doubt that the grimoire which used to be owned by Licht is now Asta’s. If this sword is to become a “support” sword, it is reasonable that this third sword can dispel magic that cannot be dispelled by Anti-Magic swords alone. Who knows? Maybe this sword can also dispel the Reincarnation Magic that Licht cast before he died.