Physically, you would need a lot of magnetic force to pull the knives from that person, like, maybe it was 2 meter away from the mc. And also, talking of the manga takes place at European Witch Hunt, which was Mid 15th Century to Mid 18th Century, and the knives were Dagger Type, and I think it was Quillon Dagger ? Would probably made of iron, and quite in the middle level of being magnetic, woun't be dragged like that.
Anyway, contonue with the illogical physics please •-•