Echoing Mass Card card_mirror_lake

What it is for

Card: fits into Right hand gear that has a free slot.

Chance to cast a Ghost strike on attack 8%. Damage against bosses +30%.

Weighs 2 of your carry capacity — and weight is what stops drops once the bag fills up.

The best source is Echoing Mass, at 0.020% per kill. You can farm it at Mirror Lake.