Urza's Sylex [The Brothers' War: Prerelease Promos]

Set: The Brothers' War: Prerelease Promos Type: Legendary Artifact Rarity: Mythic Cost: {3} {2}{W}{W}, {T}, Exile Urza's Sylex: Each player chooses six lands they control. Destroy all other permanents. Activate only as a sorcery.When Urza's Sylex is put into exile from the battlefield, you may pay {2}. If you do, search your library for a planeswalker card, reveal it, put it into your hand, then shuffle.