Silent Sentinel | Magic: The Gathering
Formats Silent Sentinel is Legal in
Official Oracle Text for Silent Sentinel
Whenever Silent Sentinel attacks, you may return target enchantment card from your graveyard to the battlefield.
Official Rulings for Silent Sentinel
2/1/2014 : If the enchantment card is an Aura, you choose a legal player or object for that Aura to enchant as it enters the battlefield. This doesn’t target the player or object, so it’s possible to enchant an opposing creature with hexproof this way, for example. If there’s no player or object the Aura can legally enchant, it stays in the graveyard.