Ogdoadic Hollow — Ruling

Effetto 1

The effect that Special Summons 1 monster from your opponent's Graveyard to your field starts a Chain and can be activated on the field. (This effect targets 1 monster in your opponent's Graveyard. Tribute 1 Reptile Effect monster you control as the cost of activating this effect.)
This effect finishes resolving by Special Summoning the targeted monster to your field. (The monster is Special Summoned with the part of the effect that sends it to the Graveyard during the End Phase already applying.)

The effect that sends all face-up monsters you control other than Reptile monsters to the Graveyard starts a Chain and activates in the Graveyard. (This effect must be activated when this face-up card in the Spell & Trap Zone is sent to the Graveyard. It does not target, and will also activate during the Damage Step.)