Thieving Sprite

Flying
When Thieving Sprite enters, target player reveals X cards from their hand, where X is the number of Faeries you control. You choose one of those cards. That player discards that card.

Modern Masters

Flying
When Thieving Sprite enters the battlefield, target player reveals X cards from his or her hand, where X is the number of Faeries you control. You choose one of those cards. That player discards that card.

Lorwyn

Flying
When Thieving Sprite comes into play, target player reveals X cards from his or her hand, where X is the number of Faeries you control. You choose one of those cards. That player discards that card.

The number of cards that are revealed is equal to the number of Faeries you control when the ability resolves.