The Gift Giver

When The Gift Giver enters the battlefield, X
target cards in your graveyard gain flashback
until the end of turn where X is the amount of
additional mana you spent to cast The Gift Giver.
The flashback cost is equal to its mana cost.
Instants and sorceries you cast cost {1} less to cast.
The Gift Givers power and toughness are equal
to the number of cards with flashback in your
graveyard.