They're just using it as a Spell they can destroy with Armor Ninjitsu Art of Alchemy. There aren't a huge number of draw 2 cards available in multiples here, and a few (like Cards of the Red Stone) can only be used once per turn, unlike the Ninjitsu Art.
Yeah, you can't search Alchemy using Notebook without a Ninja monster.
Using Notebook as sacrifice for Alchemy is a valid move in this deck, but......searching Alchemy using Notebook can't be done in this deck since there's no Ninja monster at all.
Anoymous
