You're more likely to find them in larger stores or ones in urban areas
In addition to the handbooks, there are a ton of book series, including manga, picture and chapter books, coloring books, etc
Across all of my testing with the theme, there are three standout rules to follow for the rest of the deckbuild that gives the Chaos Ritual strategy all it needs to thrive: Every build needs to have at least: 1 non-theme way to get Skull Archfiend of Chaos to the GY without requiring the Normal Summon 1 non-theme way to get 8 Levels of monster(s) to the GY, to banish for your first Ritual Summon, without requiring the Normal Summon 2+ ways to field a Level 7+ Main Deck monster, that doesnt mind being left on board, that you would also like returned to hand
With so many key staples being reprinted here, and with expansive print runs on deck, there is every reason to believe that some new players will pick up a Modern deck, and that Modern players will diversify their options by expanding their staples collection