Forum:Zombie World VS Spellbook of Knowledge

I have "Zombie World" face-up on my field. My opponent controls "Spellbook Magician of Prophecy" and activates "Spellbook of Knowledge", attempting to send the face-up "Spellbook Magician of Prophecy". Is my opponent able to use their face-up "Spellbook Magician of Prophecy" as cost? Hemarc (talk • contribs) 13:42, July 18, 2019 (UTC)