Level Eater (SDSE-EN017) [Structure Deck: Synchron Extreme]

If this card is in the Graveyard: You can target 1 Level 5 or higher monster you control; reduce its Level by 1, and if you do, Special Summon this card from the Graveyard. This face-up card on the field cannot be Tributed, except for a Tribute Summon.