Revered Relic

When Revered Relic enters the battlefield or is put into your graveyard from anywhere, return a legendary card from your graveyard to your hand.
{4}: Revered Relic becomes an X/X Construct creature with Indestructible and Lifelink until end of turn, where X is twice the number of legendary permanents on the battlefield.
Forgotten by civilisation, they eternally stand guard over forgotten secrets.