Seize the Storm

To determine the total cost of a spell, start with the mana cost or alternative cost (such as a flashback cost) you're paying, add any cost increases, then apply any cost reductions. The mana value of the spell is determined only by its mana cost, no matter what the total cost to cast the spell was.

You can cast a spell using flashback even if it was somehow put into your graveyard without having been cast.

If a card with flashback is put into your graveyard during your turn, you can cast it if it's legal to do so before any other player can take any actions.

A spell cast using flashback will always be exiled afterward, whether it resolves, is countered, or leaves the stack in some other way.

"Flashback [cost]" means "You may cast this card from your graveyard by paying [cost] rather than paying its mana cost" and "If the flashback cost was paid, exile this card instead of putting it anywhere else any time it would leave the stack."

If you cast Seize the Storm with no instant or sorcery cards in your graveyard and no cards with flashback in exile, the Elemental will start as a 0/0 creature. However, state-based actions won't be checked until after Seize the Storm has finished resolving. The Elemental will then be a 1/1 creature and survive because Seize the Storm will either be in your graveyard or in exile.