AAAA, THE HOWLING GOO

Mill 1(Put the top 1 card of your library into your graveyard): the next spell you cast costs 2 mana
of any color less to cast.
When AAA, THE HOWLING GOO enters the battlefield, mill 5
{t}: you may cast target spell from your graveyard.
{b/g}{b/g}{b/g}: put target card from your graveyard on
the top or bottom of your library.
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