Whispering Bamboo Card card_haunted_grove_1

What it is for

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

Damage against Demon +37%.

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

The best source is Whispering Bamboo, at 0.050% per kill. You can farm it at Haunted Grove.