Lavalval Chain (HA07-EN019) - Hidden Arsenal 7: Knight of Stars 1st Edition

2 Level 4 monsters // Once per turn: You can detach 1 Xyz Material from this card to activate 1 of these effects: // * Send 1 card from your Deck to the Graveyard. // * Choose 1 monster from your Deck and place it on top of your Deck.