Players have since improved on it by adding the engine into plenty of other relevant decks.
Let's look at a sample decklist.
============ Main Deck : 47 ============
Master Peace, the True Dracoslaying King x3
Gameciel, the Sea Turtle Kaiju x1
Kumongous, the Sticky String Kaiju x1
Dynamite Knuckle, the True Dracofighter x3
Ignis Heat, the True Dracowarrior x1
Aleister the Eidolon Summoner x2
Ghost Ash and Beautiful Spring x3
Ghost Ogre and Snow Rabbit x2
Spellbook Magician of Prophecy x2
Maxx "C" x2
Spellbook of Rudra x2
Pot of Desires x2
Eidolon Summoning Magic x2
Cosmic Cyclone x2
Forbidden Chalice x3
True Draco Succession x3
Disciples of the True Dracophoenix x1
Dragonic Diagram x3
Reckless Magic Circle x1
Revival of the True King x3
Apocalypse of the True Dracos x2
============ Extra Deck : 15 ============
Elysion the Eidolon Beast x2
Merkabah the Eidolon Beast x3
Magallanica the Eidolon Beast x2
Purgatorio the Eidolon Beast x2
Cocytus the Eidolon Beast x1
Raideen the Eidolon Beast x1
Caligula the Eidolon Beast x2
Constellar Ptolemy M7 x1
Abyss Dweller x1
============ Side Deck : 15 ============
Radian, the Multidimensional Kaiju x1
Maxx "C" x1
D.D. Crow x2
Harpie's Feather Duster x1
Interrupted Kaiju Slumber x1
Super Polymerization x1
Reckless Magic Circle x1
Heavy Dust Storm
Macro Cosmos x3
Imperial Order x1
By playing Spellbook Magician of Prophecy, sometimes referred to by its Japanese translated name - Batel, the deck gains easier access to Spellbook of Rudra. Spellbook of Rudra can be used to send Spellbook Magician of Prophecy directly from hand to the graveyard for the draw. Alternatively, it can make the most out of the Aleister the Invoker after it has searched Invocation.
It is common to extend the engine with cards such as Spellbook of Secrets to search out the spellbook engine. The occasional Spellbook of Fate is also commonly seen to arm the deck with more disruption strategies.
Some other players prefer to include the WindWitch engine instead of the Invoked engine when playing True Dracos. The 1st and 4th place 2017 Thailand Summer Qualifers played this variant. Others call it [Windwitch Spellbook True Draco], I prefer WindWitch-Batel-MasterPeace. #lol
The addition of the Level 2 Spellcaster Spellbook Magician of Prophecy is phenomenal. It allows the deck to diversify its choice of Synchro monsters.
- Level 2 + Level 4 Synchro Summon = HTS Psyhemuth, Powered Inzektron, Coral Dragon, Stardust Charge Warrior
- Level 6 (Synchro Monster)+ Level 4 = Level 10 Leo, the Keeper of the Sacred Tree.
- Level 2 + Level 3 + Level 4 = Trishula Dragon of the Ice Barrier.
All these additions seek to empower and make a True Draco deck unpredictable and unique. Spellbook Magician of Prophecy aims to allow a True Draco deck draw into more resources or 'outs' during games. The Invoked engine and the WindWitch engine each has their own merits, and by accessing Fusion and Synchro monsters respectively, it makes the True Draco deck less vulnerable in the face of Macro Cosmos and Mask of Restrict.
The Invoked engine is especially noteworthy for improving certain matchups such as True King Dinos, as the Invoked engine can banish the opposing graveyard resources, a currency which True King Dinos can't afford to lose.
ConclusionThe utility of the Spellbook engine extends in True Draco decks than other decks. With an additional few more Spellcaster monsters, it helps when Spellbook of Rudra is drawn into before Spellbook Magician of Prophecy. If Spellbook Magician of Prophecy is drawn into, late in the game after all copies of Spellbook of Rudra has been used, it can be used as a tribute fodder.
Finally, being in a True Draco deck, dead copies, either spell or monster can always be used for Dragonic Diagram.
Unfortunately, the addition of these engines makes a True Draco deck unable to abuse Skill Drain and Deck Lockdown. At least not without first siding out the respective affected engines.