Regardless of being illusions, they weren't entirely harmless. They made it so I could barely see. They were so bright and obscuring. The flames and the kitsune got within five feet of me.
Four knives stabbed at me through the wall of flames from different directions. This time, instead of trying to block any of the knives, I swung my sword horizontally through the flames in the directions the knives were coming from.
I figured if I could hit all four kitsune at once, I would hit the real one eventually. To my surprise, my swing cut through all four of the kitsune behind the flames and the arms and the knives they were holding disappeared.