When this card is Special Summoned by the effect of a Spellcaster-Type monster: You can target any number of your banished "Spellbook" Spell Cards; shuffle them into the Deck, and if you do, return your other banished "Spellbook" Spell Cards to your Graveyard. You can only use the effect of "Wheel of Prophecy" once per turn.
You can special summon Wheel of Prophecy with these monster’s effects. You can special summon him straight from the deck with Fool of Prophecy’s effect, but another thing you can do if you want to swarm the field is special summon Reaper with Fool’s effect. And then with Reaper’s effect special summon Wheel of Prophecy.
These cards specifically require that you banish your Spellbook cards. Use Wheel of Prophecy’s effect to retrieve your Banished Spellbooks.
Here are some Spellbook spell cards that support the Prophecy Archetype and Spellcasters in general. Some cards you do not want to return to the deck, for example Spell Library of the Crescent is useless in your hand and/or deck late game so it is better to return it to the graveyard.