Scion of Elements

Flash, Trample
When Scion of Elements enters the battlefield,
exile target spell. You may cast that card without paying its mana cost as long as you control Scion
of Elements.
Whenever Scion of Elements deals combat
damage to a player, exile cards from the top
of your library until you exile a blue card, then
cast that card without paying its mana cost.
"I am all."