Chthonian Emperor Dragon [TAEV-EN019] Ultimate Rare Legendary Collection 2 if you have a Spellcaster-Type

if you have a Spellcaster-Type monster on your side of the field or in your Graveyard: You can return 1 "Spellbook" Spell Card from your Graveyard to the bottom of your Deck

and if you do that

Set: Duel Terminal 4 Card type: Synchro/Effect Monster Rarity: Ultra Rare Attack: 2400 Defense: 1700 1 Dragon-Type Tuner + 1 or more non-Tuner Winged Beast-Type monsters Once per turn

Set: Sun & Moon: Crimson Invasion Type: Colorless Rarity: Holo Rare Retreat cost: Colorless

Chthonian Emperor Dragon [TAEV-EN019] Ultimate Rare Legendary Collection 2 if you have a Spellcaster-TypeSet: Tactical Evolution Card type: Gemini Monster Rarity: Ultimate Rare Attack: 2400 Defense: 1500 This card is treated as a Normal Monster while face up on the field or in the Graveyard. While this card is face up on the field, you can Normal Summon it to have it be treated as an Effect Monster with this effect: This card can attack twice during the same Battle Phase.