Azem\'s Crystal

When Azem’s Crystal enters the battlefield, summon seven colorless +1/+1 hero tokens into the battlefield with Haste and Vigilance.{Lns} When hero tokens summoned by Azem’s Crystal are destroyed, gain 1 life for each.{Lns} After all hero tokens summoned by Azem’s Crystal are destroyed, return it to the owner’s library, then shuffle.{Lns}