Sinister Yorishiro (SR06-EN040) [Structure Deck: Lair of Darkness]

Each turn, 1 Level 5 or higher Fiend monster you Normal Summon can be Summoned without Tributing. If exactly 1 Normal Summoned/Set Level 5 or higher Fiend monster (and no other cards) would be destroyed, you can send this card to the GY instead.