Hidden Constellation

You may cast a legendary Celestial Aura from
your hand without paying its mana cost.
Otherwise, search your library for a legendary
Celestial Aura, reveal it, put it into your hand,
then shuffle your library.
Radiance —Creatures that share a color with
a legendary Celestial Aura you cast or put into
your hand with Hidden Constellation this turn
get +1/+1 until end of turn.