Astrea, Heir to Nyx

Convoke.
If no mana was spent to cast Astrea, Heir to Nyx,
she enters the battlefield with a Divinity counter.
(A permanent with a Divinity counter has Indestructible.)
{b}, sacrifice an Enchantment : you lose a life and
draw a card.
{g/w}{g/w}, remove all Divinity counters from Astrea,
Heir to Nyx : return all Enchantment cards from
your graveyard to the battlefield.