Galvanic Iteration

If the spell that's copied has an X whose value was determined as it was cast, the copy has the same value of X.

The copy that Galvanic Iteration's ability creates is created on the stack, so it's not "cast." Abilities that trigger when a player casts a spell won't trigger.

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 resolve one Galvanic Iteration after another (or cast the same one with flashback), the second Galvanic Iteration will be copied. That copy and spell each resolve, creating two delayed triggered abilities. The next spell you cast after that will be copied twice. If that spell is also a Galvanic Iteration, the following spell will be copied three times, and so on.

You must still follow any timing restrictions and permissions, including those based on the card's type. For instance, you can cast a sorcery using flashback only when you could normally cast a sorcery.

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.

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 copy is created even if the spell that caused Galvanic Iteration's ability to trigger has been countered by the time that ability resolves. The copy resolves before the original spell.

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