Urza's Sylex
From The Brothers' War set
Urza's Sylex
Legendary Artifact
,
, 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
. If you do, search your library for a planeswalker card, reveal it, put it into your hand, then shuffle.