Familiar-Possessed - Eria (SDCH-EN038) [Structure Deck: Spirit Charmers]

You can Special Summon this card (from your hand or your Deck) by sending 1 face-up "Eria the Water Charmer" and 1 face-up WATER monster you control to the GY. If this card Special Summoned by its own effect attacks a Defense Position monster, inflict piercing battle damage.