Livraison gratuite (voir cond.). The black mortal blade is capable of killing immortals as it is able to wound Kuro and kill you (which is corrected by the game tho) and it also probably doesn't require the whole killing it's wielder thing as Genichiro isn't exactly immortal and neither is Isshin. On the other hand, it might need the killing but Genichiro is able to wield it.