Mermail Abyssmegalo (SHVA-EN037) - Shadows in Valhalla 1st Edition

You can discard 2 other WATER monsters to the Graveyard; Special Summon this card from your hand. When you do: You can add 1 "Abyss-" Spell/Trap Card from your Deck to your hand. You can Tribute 1 other face-up Attack Position WATER monster; this card can make a second attack during each Battle Phase this turn.