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Even though it makes its Attack 0, you still get the effects which is why it's so good.
Chalice of the Void Full Art by Kieran Yanner
Unfortunately, most Tomes are either Seeker-class anyway, or don't really work without extra setup she can't do without access to the other cards of same class, so she loses more than she gains
Trainer Gallery cards have done this a bit, but I would love to see more
Then, 1 of your opponent's Digimon with no digivolution cards can't attack or block until the end of your opponent's next turn