You can send 1 «Atlantean» monster from your Deck to the Graveyard, except «Neptabyss, the Atlantean Prince»; add 1 «Atlantean» card from your Deck to your hand, except «Neptabyss, the Atlantean Prince». If this card is sent to the Graveyard to activate a WATER monster’s effect: Target 1 «Atlantean» monster in your Graveyard, except «Neptabyss, the Atlantean Prince»; Special Summon it. You can only use each effect of «Neptabyss, the Atlantean Prince» once per turn.