Lightning Dragon

Flying
Echo {2}{R}{R} (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)
{R}: Lightning Dragon gets +1/+0 until end of turn.

Thundering Rebuke

Thundering Rebuke deals 4 damage to target creature or planeswalker.

Spark Jolt

Spark Jolt deals 1 damage to any target. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Thunderblust

Haste
Thunderblust has trample as long as it has a -1/-1 counter on it.
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Chain Lightning

Chain Lightning deals 3 damage to any target. Then that player or that permanent's controller may pay {R}{R}. If the player does, they may copy this spell and may choose a new target for that copy.

Lightning Strike

Lightning Strike deals 3 damage to any target.

Thunderwave

Roll a d20.
1—9 | Thunderwave deals 3 damage to each creature.
10—19 | You may choose a creature. Thunderwave deals 3 damage to each creature not chosen this way.
20 | Thunderwave deals 6 damage to each creature your opponents control.

Lightning Blast

Lightning Blast deals 4 damage to any target.

Ball Lightning

Trample (This creature can deal excess combat damage to the player or planeswalker it's attacking.)
Haste (This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice this creature.

Living Lightning

When Living Lightning dies, return target instant or sorcery card from your graveyard to your hand.

Thunderous Wrath

Thunderous Wrath deals 5 damage to any target.
Miracle {R} (You may cast this card for its miracle cost when you draw it if it's the first card you drew this turn.)

Lightning Axe

As an additional cost to cast this spell, discard a card or pay {5}.
Lightning Axe deals 5 damage to target creature.

Lightning Shrieker

Flying, trample, haste
At the beginning of the end step, Lightning Shrieker's owner shuffles it into their library.

Lightning Spear

Equipped creature gets +1/+0 and has trample.
{2}{R}, Sacrifice Lightning Spear: It deals 3 damage to any target.
Equip {1}

Rite of the Raging Storm

Creatures named Lightning Rager can't attack you or planeswalkers you control.
At the beginning of each player's upkeep, that player creates a 5/1 red Elemental creature token named Lightning Rager. It has trample, haste, and "At the beginning of the end step, sacrifice this creature."

Thunderbolt

Choose one —
• Thunderbolt deals 3 damage to target player or planeswalker.
• Thunderbolt deals 4 damage to target creature with flying.

Conduit of Emrakul

Whenever Conduit of Emrakul attacks, add {C}{C} at the beginning of your next main phase this turn.

Conduit of Storms

Whenever Conduit of Storms attacks, add {R} at the beginning of your next main phase this turn.
{3}{R}{R}: Transform Conduit of Storms.

Conduit of Storms // Conduit of Emrakul

Barbed Lightning

Choose one —
• Barbed Lightning deals 3 damage to target creature.
• Barbed Lightning deals 3 damage to target player or planeswalker.
Entwine {2} (Choose both if you pay the entwine cost.)

Lightning Mauler

Soulbond (You may pair this creature with another unpaired creature when either enters. They remain paired for as long as you control both of them.)
As long as Lightning Mauler is paired with another creature, both creatures have haste.

Stormbreath Dragon

Flying, haste, protection from white
{5}{R}{R}: Monstrosity 3. (If this creature isn't monstrous, put three +1/+1 counters on it and it becomes monstrous.)
When Stormbreath Dragon becomes monstrous, it deals damage to each opponent equal to the number of cards in that player's hand.

Deflecting Swat

If you control a commander, you may cast this spell without paying its mana cost.
You may choose new targets for target spell or ability.

Mountain

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Lightning Hounds

Sparkspitter

{R}, {T}, Discard a card: Create a 3/1 red Elemental creature token named Spark Elemental. It has trample, haste, and "At the beginning of the end step, sacrifice Spark Elemental."

Forked Lightning

Forked Lightning deals 4 damage divided as you choose among one, two, or three target creatures.

Arc Lightning

Arc Lightning deals 3 damage divided as you choose among one, two, or three targets.

Reckless Barbarian

Sacrifice Reckless Barbarian: Add {R}{R}.

Hellspark Elemental

Trample, haste
At the beginning of the end step, sacrifice Hellspark Elemental.
Unearth {1}{R} ({1}{R}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Rolling Thunder

Rolling Thunder deals X damage divided as you choose among any number of targets.

Blitz of the Thunder-Raptor

Blitz of the Thunder-Raptor deals damage to target creature or planeswalker equal to the number of instant and sorcery cards in your graveyard. If that creature or planeswalker would die this turn, exile it instead.

Hell's Thunder

Flying, haste
At the beginning of the end step, sacrifice Hell's Thunder.
Unearth {4}{R} ({4}{R}: Return this card from your graveyard to the battlefield. It gains haste. Exile it at the beginning of the next end step or if it would leave the battlefield. Unearth only as a sorcery.)

Thundering Raiju

Haste
Whenever Thundering Raiju attacks, put a +1/+1 counter on target creature you control. Then Thundering Raiju deals X damage to each opponent, where X is the number of modified creatures you control other than Thundering Raiju. (Equipment, Auras you control, and counters are modifications.)

Mindsparker

First strike (This creature deals combat damage before creatures without first strike.)
Whenever an opponent casts a white or blue instant or sorcery spell, this creature deals 2 damage to that player.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Rhystic Lightning

Rhystic Lightning deals 4 damage to any target unless that permanent's controller or that player pays {2}. If they do, Rhystic Lightning deals 2 damage to the permanent or player.

Lightning Mare

This spell can't be countered.
Lightning Mare can't be blocked by blue creatures.
{1}{R}: Lightning Mare gets +1/+0 until end of turn.

Burst Lightning

Kicker {4} (You may pay an additional {4} as you cast this spell.)
Burst Lightning deals 2 damage to any target. If this spell was kicked, it deals 4 damage instead.

Lightning Javelin

Lightning Javelin deals 3 damage to any target. Scry 1. (Look at the top card of your library. You may put that card on the bottom.)

Seize the Storm

Create a red Elemental creature token with trample and "This creature's power and toughness are each equal to the number of instant and sorcery cards in your graveyard plus the number of cards with flashback you own in exile."
Flashback {6}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Lightning Cloud

Whenever a player casts a red spell, you may pay {R}. If you do, Lightning Cloud deals 1 damage to any target.

Lightning Visionary

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)

Myriad Landscape

Myriad Landscape enters tapped.
{T}: Add {C}.
{2}, {T}, Sacrifice Myriad Landscape: Search your library for up to two basic land cards that share a land type, put them onto the battlefield tapped, then shuffle.

Thunder Dragon

Flying
When Thunder Dragon enters, it deals 3 damage to each creature without flying.

Storm King's Thunder

When you next cast an instant or sorcery spell this turn, copy that spell X times. You may choose new targets for the copies.

Lightning Elemental

Haste (This creature can attack and {T} as soon as it comes under your control.)

Thunderbreak Regent

Flying
Whenever a Dragon you control becomes the target of a spell or ability an opponent controls, Thunderbreak Regent deals 3 damage to that player.

Shower of Sparks

Shower of Sparks deals 1 damage to target creature and 1 damage to target player or planeswalker.

Lightning Phoenix

Flying, haste
Lightning Phoenix can't block.
At the beginning of your end step, if an opponent was dealt 3 or more damage this turn, you may pay {R}. If you do, return Lightning Phoenix from your graveyard to the battlefield.

Etali, Primal Storm

Whenever Etali attacks, exile the top card of each player's library, then you may cast any number of spells from among those cards without paying their mana costs.

Thundermaw Hellkite

Flying
Haste (This creature can attack and {T} as soon as it comes under your control.)
When Thundermaw Hellkite enters, it deals 1 damage to each creature with flying your opponents control. Tap those creatures.

Thrill of Possibility

As an additional cost to cast this spell, discard a card.
Draw two cards.

Lightning Serpent

Trample, haste
Lightning Serpent enters with X +1/+0 counters on it.
At the beginning of the end step, sacrifice Lightning Serpent.

Resounding Thunder

Resounding Thunder deals 3 damage to any target.
Cycling {5}{B}{R}{G} ({5}{B}{R}{G}, Discard this card: Draw a card.)
When you cycle Resounding Thunder, it deals 6 damage to any target.

Spark Elemental

Trample, haste (This creature can deal excess combat damage to the player or planeswalker it's attacking. This creature can attack and {T} as soon as it comes under your control.)
At the beginning of the end step, sacrifice Spark Elemental.

Rogue's Passage

{T}: Add {C}.
{4}, {T}: Target creature can't be blocked this turn.

Lightning Rift

Whenever a player cycles a card, you may pay {1}. If you do, Lightning Rift deals 2 damage to any target.

Sparktongue Dragon

Flying
When Sparktongue Dragon enters, you may pay {2}{R}. When you do, it deals 3 damage to any target.

Storm's Wrath

Storm's Wrath deals 4 damage to each creature and each planeswalker.

Leyline of Lightning

If Leyline of Lightning is in your opening hand, you may begin the game with it on the battlefield.
Whenever you cast a spell, you may pay {1}. If you do, Leyline of Lightning deals 1 damage to target player or planeswalker.

Warstorm Surge

Whenever a creature you control enters, it deals damage equal to its power to any target.

Arcane Signet

{T}: Add one mana of any color in your commander's color identity.

Lightning Surge

Lightning Surge deals 4 damage to any target.
Threshold — If seven or more cards are in your graveyard, instead Lightning Surge deals 6 damage to that permanent or player and the damage can't be prevented.
Flashback {5}{R}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Weaver of Lightning

Reach (This creature can block creatures with flying.)
Whenever you cast an instant or sorcery spell, Weaver of Lightning deals 1 damage to target creature an opponent controls.