Mermail Abyssbalaen

Level 7 WATER/Aqua Effect
2500 ATK / 2000 DEF

You can discard 4 other "Mermail" monsters to the Graveyard; Special Summon this card from your hand. When you do: Target cards your opponent controls, up to the number of "Mermail" monsters in your Graveyard (if possible); this card gains 500 ATK, and if it does, destroy those targets (if any). You can Tribute 1 other face-up Attack Position "Mermail" monster; this card gains the following effect this turn.
● At the start of the Damage Step, if this card battles a Defense Position monster: Destroy that monster.

Rulings – Yugipedia

Printings:

Lord of the Tachyon Galaxy: LTGY-EN083 (Ultimate Rare) - 2013-05-17
Lord of the Tachyon Galaxy: LTGY-EN083 (Ultra Rare) - 2013-05-17
2014 Mega-Tin Mega Pack: MP14-EN055 (Ultra Rare) - 2014-08-28

Prices:

Cardmarket: 0.23 €
TCGplayer: $ 0.31