The player must defeat a Darkwraith located at the bottom of a tower in the High Wall of Lothric after receiving the Lift Chamber Key provided by Ringfinger Leonhard once they have obtained a Pale Tongue.
From the Tower on the Wall bonfire, make way to the bottom of the tower and unlock the barred door with the key given by Leonhard. Ride the lift down and fight the Darkwraith there. The item will be automatically added to the player's inventory once he dies.
Using this infinite consumable will allow a player to invade another player's world. The player will invade anyone within approximately 15 soul levels beneath and at any range above the player's soul level within the same playthrough.