Astral Moth Card card_starlit_stairs_1

What it is for

Card: fits into Garment gear that has a free slot.

Damage taken from Ghost element −40%.

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

The best source is Astral Moth, at 0.050% per kill. You can farm it at Starlit Stairs.