Asta has Licts magic instead of anti-magic, but needs his grimoire to use his magic. He still gets picked on before the ceremony, but after everyone sees his four leaf grimoire and the power of his first sword when he swings it even Yuno realizes that he's no match for Asta.

In this story Astas power will mean he is constantly absorbing magic from the  air, so people can't sense him. He will however be able to sense there magic, absorb there spells and reforge his swords to make them stronger and/or more controllable. Also all of his spells are sword creation magic.