The messenger steps in
Usually, in the case of the Black Swordsman's power, whenever he used it would negate their ability. In terms of energy, it stopped things as well, but there were some instances where things could still work.
The Black Swordsman's own body was quite unique, after all. In fact, he could still draw out his own powers even when using the sword. His body was unaffected by his own powers, which was how Russ was able to use his powers, to summon himself as the Black Swordsman and continue to use his powers.
With a special sword that drew out one's power, would it be the same?
Rushing forward, Russ, with the two swords, thrust them. Both of the swords started to cover themselves in the black aura, and it seemed like his power was staying. Now it was almost like he had two of the same weapons in his hands.
As it stabbed into the centre of Luce's stomach, he felt it twist and turn inwards until the swords had pierced the inside of his body.