yugioh cards unaffected by card effects Yugioh: Can Very Fun Dragon Affect Monsters? Quick Effect | Yu-Gi-Oh! Wiki

#Yuu One PieceList of Exhibits ONE PIECE CARD GAME One Piece Card Game Romance Dawn SEC Secret Parallel OP01-120 Shanks This item is used to prevent claims even if it is a beautiful or complete item

Pokemon (Promo) $52.28 A Cheeky Lugia Appearance The most valuable entry commands a massive lead over its competition, more than doubling its next closest competitor's value

In this DLC, Spectrier can fuse with Calyrex, with the end result looking a bit menacing

That explains the demand for this card, and it's also likely to be in fairly limited supply, given that it was only printed in the Warhammer Commander decks, which always get snapped up swiftly when a new batch is released