Its updated Oracle text appears above
Absolute Virtue Adelbert Steiner Aerith Gainsborough Ambrosia Whiteheart Ashe, Princess of Dalmasca Bahamut, Warden of Light Beatrix, Loyal General Cecil, Redeemed Paladin Choco, Seeker of Paradise Cid, Timeless Artificer Cloud, Midgar Mercenary Cloud, Planet's Champion Crystallized Serah Dion, Bahamut's Dominant G'raha Tia Garnet, Princess of Alexandria Giott, King of the Dwarves Hope Estheim Hydaelyn, the Mothercrystal Joshua, Phoenix's Dominant Judge Magister Gabranth Lightning, Army of One Minwu, White Mage Noctis, Prince of Lucis Phoenix, Warden of Fire Rinoa Heartilly Rosa, Resolute White Mage Rufus Shinra Serah Farron Snow Villiers Squall, SeeD Mercenary Stiltzkin, Moogle Merchant The Wind Crystal Tidus, Blitzball Star Venat, Heart of Hydaelyn Yuna, Hope of Spira Zack Fair Zidane, Tantalus Thief
The second reason is that Dragon Ruler used to win against Spellbook
C Common Skill Successor X TRAP Target 1 face-up monster you control
Until end of turn, your life total cant change, and permanents you control gain hexproof and indestructible