Teferi's Response

Instant, 1U (2)
Counter target spell or ability an opponent controls that targets a land you control. If a permanent's ability is countered this way, destroy that permanent.
Draw two cards.
Illus. Scott Bailey

Crystal Keep Rulings Summaries

• Remember that a spell only targets something if it uses the word "target" in its text. For example, Armageddon is not targeted. [D'Angelo 2000/10/14]
• If at the time this spell resolves the targeted spell is no longer targeting a land you control (either because the land left play or because you no longer control it), then this spell is countered due to have an illegal target. [D'Angelo 2007/03/10]

Format Legality	Legal in Vintage, Legacy Banned in Extended, Standard
Printings (1/6)	Invasion (Rare)