Black Eye Orb (Dark Souls III)

Availability
Found on Rosaria, Mother of Rebirth's body after visiting her and talking to Ringfinger Leonhard.

Upon defeating Ringfinger Leonhard in his world the player will obtain the Soul of Rosaria, Crescent Moon Sword, and his Silver Mask.

Usage
Used to invade Ringfinger Leonhard in the room above the Aldrich, Devourer of Gods bonfire (Qwynever's chamber from the original Dark Souls).