Rulings

• 2012-10-01
  If Detention Sphere leaves the battlefield before its enters-the-battlefield ability has resolved, its leaves-the-battlefield ability will trigger and do nothing. Then the enters-the-battlefield ability will resolve and exile the targeted nonland permanent and other permanents with that name indefinitely.
• 2012-10-01
  If the target nonland permanent is an illegal target when the enters-the-battlefield ability tries to resolve, it will be countered and none of its effects will happen. No permanents will be exiled, including those with the same name as the target.
• 2012-10-01
  The enters-the-battlefield ability has only one target. The other permanents with that name aren't targeted. For example, a permanent with protection from white will be exiled if it has the same name as the target nonland permanent.
• 2012-10-01
  Although the target of the enters-the-battlefield ability must not be a land, lands with the same name as that permanent will be exiled.