Glad to hear you're keen on my game! :)
If you're lacking a good Tarot Deck, one resource you can use is this Tiny Tarot browser app that's hosted here on itch.io:
https://raindrinker.itch.io/tiny-tarot
This app currently only lets you draw and shuffle around Major Arcana cards....which works out nice, since the gameplay mechanics of LAST CHARGE OF THE SENTRY ARCANES use a Tarot deck that's split apart into its Major and Minor Arcana cards.
With the Tiny Tarot app and a normal deck of playing cards, you should be able to play LCotSA with little issue.