This strategy has a little added twinkle in FIN, with both The Emperor of Palamecia and Shantotto, Tactician Magician giving you added bonuses if you spend 4 or more mana to cast your noncreature spells
Other than having to retroactively update dozens of previous cards - something done with some keystrokes in digital form - are there any downsides to creating the Book subtype
For a long time now, black decks have basically been slave to Gray Merchant or Whip of Erebos in terms of lifegain
Channeler will have to attack every turn once Delirious, but this isnt much of an issue for tempo decks like Legacy Izzet Delver that are trying to end the game relatively fast
The right binder with EZD rings, hard covers, and premium trading card pages will keep your cards safely protected for decades
Ok, World Breaker technically does that as a cast trigger, but you get the point