Sky Castle of Drago Phantom Thief, "Lebla Maurice"

You may use this card as your buddy; if this card is in your buddy zone and your flag is "Magic World", you cannot call monsters other than "Drago Phantom Thief", and when your opponent's cast spell would be put from hand to drop zone, put it face down in your opponent's spell area as "Magic Treasure" instead.
If your buddy is a spell, put up to four cards from the top of your opponent's deck into your opponent's spell area face down as "Magic Treasure". You may only cast "Sky Castle of Drago Phantom Thief, "Lebla Maurice"" once per turn.