In the universe of The Witcher, the ability to touch silver is significant as it indicates that a character is not a magical beast or a certain kind of monster. Silver is known to repel almost all magical creatures due to their sensitivity to the metal. Therefore, Nivellen being able to touch silver suggests that he is not a supernatural foe, such as a necrophage, therianthrope, cursed one, shapeshifter, wraith, or vampire. This is a key detail in understanding Nivellen's character and his role in The Witcher series.