This is because Murders at Karlov Manor and Duskmourn: House of Shadows both heavily feature their own face-down mechanics
If this spells madness cost was paid, instead create X of those tokens and you gain X life
Effects like on Prosper, Tome-Bound allow you to cast cards that the original card exiled, plot cards and suspend cards like Arc Blade can be cast from exile
Which ones have all been released
[19] Romin learned that the Ramen Hut was closing down, so she accompanied Yuga, Gavin and Kaizo to the restaurant, where they found the despondent shopkeeper, who explained he had been out-competed by the new GastroByte and that he would close after making a last bowl of ramen
Kaiju Gadarla If I only had Jizukiru, there would be too many situations where I couldn't use Jizukiru as material, and Kaijus are simply strong, so I increased the count