When using Karnstein Armlets, if you have the Void fragment "Echo of Leeching" equipped, any time you melee kill an enemy at full health, some kind of interaction occurs that causes Vampire's Caress buff to appear on screen, but has a sort of delayed activation. During this delay, taking additional damage from enemies seems to extend that delay to the point where the buff will be on screen but doing nothing all the way until you die. Very annoying because when they DO work, leeching and Karnsteins feel very nice together. As of right now it is way too unpredictable to consider using as this bug has killed me many many times.