If a card(s) is sent from the Deck to the Graveyard: Target 1 card in either player's Graveyard; shuffle it into the Deck, also neither player can send cards from the Deck to the Graveyard for the rest of this turn.
Sending 2 or 3 cards to the GY, you chose the one you want and you shuffle it into your deck. Against a CA deck or a REZD deck, you send back your opponent cards in his deck, preventing him to use them... But with LS on your field, you'll probably lose because your monsters / back row are too weak. This deck is too slow. Too bad.