Huatli's Aria

Signature Spell. This card can be your commander.
This card costs {2} additional mana for every time it
has been cast from your command zone.
Look at the top card of your library. The next creature spell you cast this turn may be cast as
though it had flash, can't be countered and may
be cast from the top of your library. A creature
cast this way gains haste, trample and +X/+X
until end of turn, where X equals the amount of
mana spent to cast this spell.