Gisela, Blade of Goldnight

Flying, first strike
If a source would deal damage to an opponent or a permanent an opponent controls, that source deals double that damage to that player or permanent instead.
If a source would deal damage to you or a permanent you control, prevent half that damage, rounded up.

In the Web of War

Whenever a creature you control enters, it gets +2/+0 and gains haste until end of turn.

Assault Strobe

Target creature gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Stranglehold

Your opponents can't search libraries.
If an opponent would begin an extra turn, that player skips that turn instead.

Auramancer

When Auramancer enters, you may return target enchantment card from your graveyard to your hand.

Repercussion

Whenever a creature is dealt damage, Repercussion deals that much damage to that creature's controller.

Gratuitous Violence

If a creature you control would deal damage to a permanent or player, it deals double that damage instead.

Sunhome Enforcer

Whenever Sunhome Enforcer deals combat damage, you gain that much life.
{1}{R}: Sunhome Enforcer gets +1/+0 until end of turn.

Goblin Charbelcher

{3}, {T}: Reveal cards from the top of your library until you reveal a land card. Goblin Charbelcher deals damage equal to the number of nonland cards revealed this way to any target. If the revealed land card was a Mountain, Goblin Charbelcher deals double that damage instead. Put the revealed cards on the bottom of your library in any order.

Tectonic Instability

Whenever a land enters, tap all lands its controller controls.

Boros Guildmage

{1}{R}: Target creature gains haste until end of turn.
{1}{W}: Target creature gains first strike until end of turn.

Stun Sniper

{1}, {T}: Stun Sniper deals 1 damage to target creature. Tap that creature.

Furnace of Rath

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Goblin Bomb

At the beginning of your upkeep, you may flip a coin. If you win the flip, put a fuse counter on Goblin Bomb. If you lose the flip, remove a fuse counter from Goblin Bomb.
Remove five fuse counters from Goblin Bomb and sacrifice it: It deals 20 damage to target player or planeswalker.

Avatar of Slaughter

All creatures have double strike and attack each combat if able.

Spitemare

Whenever Spitemare is dealt damage, it deals that much damage to any target.

Crystal Ball

{1}, {T}: Scry 2. (Look at the top two cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Devoted Caretaker

{W}, {T}: Target permanent you control gains protection from instant spells and from sorcery spells until end of turn.

Master Warcraft

Cast this spell only before attackers are declared.
You choose which creatures attack this turn.
You choose which creatures block this turn and how those creatures block.

Overblaze

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 {2}{R}{R} (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.)

True Conviction

Creatures you control have double strike and lifelink.

Sol Ring

Fireshrieker

Equipped creature has double strike. (It deals both first-strike and regular combat damage.)
Equip {2} ({2}: Attach to target creature you control. Equip only as a sorcery.)

Dimensional Breach

Exile all permanents. For as long as any of those cards remain exiled, at the beginning of each player's upkeep, that player returns one of the exiled cards they own to the battlefield.

Aggravated Assault

{3}{R}{R}: Untap all creatures you control. After this main phase, there is an additional combat phase followed by an additional main phase. Activate only as a sorcery.

Jokulhaups

Destroy all artifacts, creatures, and lands. They can't be regenerated.

Razia, Boros Archangel

Flying, vigilance, haste
{T}: The next 3 damage that would be dealt to target creature you control this turn is dealt to another target creature instead.

Breaking Point

Any player may have Breaking Point deal 6 damage to them. If no one does, destroy all creatures. Creatures destroyed this way can't be regenerated.

Lightning Helix

Lightning Helix deals 3 damage to any target and you gain 3 life.

Mountain

Sunhome, Fortress of the Legion

{T}: Add {C}.
{2}{R}{W}, {T}: Target creature gains double strike until end of turn.

Basandra, Battle Seraph

Flying
Players can't cast spells during combat.
{R}: Target creature attacks this turn if able.

Cataclysm

Each player chooses from among the permanents they control an artifact, a creature, an enchantment, and a land, then sacrifices the rest.

Lightning Greaves

Equipped creature has haste and shroud. (It can't be the target of spells or abilities.)
Equip {0}

Curse of Bloodletting

Enchant player
If a source would deal damage to enchanted player, it deals double that damage to that player instead.

Quest for Pure Flame

Whenever a source you control deals damage to an opponent, you may put a quest counter on Quest for Pure Flame.
Remove four quest counters from Quest for Pure Flame and sacrifice it: If any source you control would deal damage to a permanent or player this turn, it deals double that damage to that permanent or player instead.

Razia's Purification

Each player chooses three permanents they control, then sacrifices the rest.

Greater Auramancy

Other enchantments you control have shroud. (A permanent with shroud can't be the target of spells or abilities.)
Enchanted creatures you control have shroud.

Boros Signet

Price of Glory

Whenever a player taps a land for mana, if it's not that player's turn, destroy that land.

Karmic Justice

Whenever a spell or ability an opponent controls destroys a noncreature permanent you control, you may destroy target permanent that opponent controls.

Charmbreaker Devils

At the beginning of your upkeep, return an instant or sorcery card at random from your graveyard to your hand.
Whenever you cast an instant or sorcery spell, Charmbreaker Devils gets +4/+0 until end of turn.

Concerted Effort

At the beginning of each upkeep, creatures you control gain flying until end of turn if a creature you control has flying. The same is true for fear, first strike, double strike, landwalk, protection, trample, and vigilance.

Adamaro, First to Desire

Adamaro, First to Desire's power and toughness are each equal to the number of cards in the hand of the opponent with the most cards in hand.

Waves of Aggression

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase.
Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

Akroma, Angel of Fury

This spell can't be countered.
Flying, trample, protection from white and from blue
{R}: Akroma, Angel of Fury gets +1/+0 until end of turn.
Morph {3}{R}{R}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)

Firemane Angel

Flying, first strike
At the beginning of your upkeep, if Firemane Angel is in your graveyard or on the battlefield, you may gain 1 life.
{6}{R}{R}{W}{W}: Return Firemane Angel from your graveyard to the battlefield. Activate only during your upkeep.

Boros Garrison

Boros Garrison enters tapped.
When Boros Garrison enters, return a land you control to its owner's hand.
{T}: Add {R}{W}.

Reverberate

Copy target instant or sorcery spell. You may choose new targets for the copy.

Cleansing Meditation

Destroy all enchantments.
Threshold — If seven or more cards are in your graveyard, instead destroy all enchantments, then return all cards in your graveyard destroyed this way to the battlefield.

Morningtide

Austere Command

Choose two —
• Destroy all artifacts.
• Destroy all enchantments.
• Destroy all creatures with mana value 3 or less.
• Destroy all creatures with mana value 4 or greater.

Balefire Liege

Other red creatures you control get +1/+1.
Other white creatures you control get +1/+1.
Whenever you cast a red spell, Balefire Liege deals 3 damage to target player or planeswalker.
Whenever you cast a white spell, you gain 3 life.

Fireblast

You may sacrifice two Mountains rather than pay this spell's mana cost.
Fireblast deals 4 damage to any target.

Psychotic Fury

Target multicolored creature gains double strike until end of turn.
Draw a card.

Captain's Maneuver

The next X damage that would be dealt to target creature, planeswalker, or player this turn is dealt to another target creature, planeswalker, or player instead.

Battle Mastery

Enchant creature
Enchanted creature has double strike. (It deals both first-strike and regular combat damage.)

Double Cleave

Armillary Sphere

{2}, {T}, Sacrifice Armillary Sphere: Search your library for up to two basic land cards, reveal them, put them into your hand, then shuffle.

Fire Servant

If a red instant or sorcery spell you control would deal damage, it deals double that damage instead.

Lightning Bolt

Lightning Bolt deals 3 damage to any target.

Loxodon Warhammer

Equipped creature gets +3/+0 and has trample and lifelink.
Equip {3}

Reflect Damage

The next time a source of your choice would deal damage this turn, that damage is dealt to that source's controller instead.

Swiftfoot Boots

Equipped creature has hexproof and haste. (It can't be the target of spells or abilities your opponents control. It can attack and {T} no matter when it came under your control.)
Equip {1} ({1}: Attach to target creature you control. Equip only as a sorcery.)

Citadel of Pain

At the beginning of each player's end step, Citadel of Pain deals X damage to that player, where X is the number of untapped lands they control.

Plains

Rage Reflection

Creatures you control have double strike.

Scourge of the Nobilis

Enchant creature
As long as enchanted creature is red, it gets +1/+1 and has "{R/W}: This creature gets +1/+0 until end of turn."
As long as enchanted creature is white, it gets +1/+1 and has lifelink. (Damage dealt by the creature also causes its controller to gain that much life.)