Nunu, the Ogdoadic Remnant (ANGU-EN001) [Ancient Guardians]

You can send this card from your hand to the GY; send 1 DARK Reptile monster from your Deck to the GY. If you control no monsters, or you control an "Ogdoadic" monster: You can Special Summon this card from your GY, but banish it when it leaves the field, also you cannot Special Summon monsters, except Reptile monsters, while this card is face-up in the Monster Zone. You can only use each effect of "Nunu, the Ogdoadic Remnant" once per turn.