Arrow Storm

Lightning Surge deals 4 damage to any target.

Threshold — If there are seven or more cards in your graveyard, instead Lightning Surge deals 6 damage to that permanent or player and the damage can't be prevented.

Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Damage can't be prevented this turn. If a source you control would deal damage this turn to an opponent or a permanent an opponent controls, it deals triple that damage instead.

Flashback (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Damage can't be prevented this turn. If a source you control would deal damage this turn, it deals double that damage instead.

Shower of Coals deals 2 damage to each of up to three targets.

Threshold — Shower of Coals deals 4 damage to each of those permanents and/or players instead if there are seven or more cards in your graveyard.

Until end of turn, permanents you control gain ": This permanent deals 1 damage to any target."

Each time target permanent would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.

Splice onto Arcane (As you cast an Arcane spell, you may reveal this card from your hand and pay its splice cost. If you do, add this card's effects to that spell.)