Mirror Match

Cast this spell only during the declare blockers step.
For each creature attacking you or a planeswalker you control, create a token that's a copy of that creature and that's blocking that creature. Exile those tokens at end of combat.

Holy Day

Prevent all combat damage that would be dealt this turn.

Arachnogenesis

Create X 1/2 green Spider creature tokens with reach, where X is the number of creatures attacking you. Prevent all combat damage that would be dealt this turn by non-Spider creatures.

Mirrorweave

Each other creature becomes a copy of target nonlegendary creature until end of turn.

Misdirection

You may exile a blue card from your hand rather than pay this spell's mana cost.
Change the target of target spell with a single target.

Powerstone Minefield

Whenever a creature attacks or blocks, Powerstone Minefield deals 2 damage to it.

Lightmine Field

Whenever one or more creatures attack, Lightmine Field deals damage to each of those creatures equal to the number of attacking creatures.

Kynaios and Tiro of Meletis

At the beginning of your end step, draw a card. Each player may put a land card from their hand onto the battlefield, then each opponent who didn't draws a card.

Avatar of Slaughter

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

Obscuring Haze

If you control a commander, you may cast this spell without paying its mana cost.
Prevent all damage that would be dealt this turn by creatures your opponents control.

Counterspell

Arcane Denial

Counter target spell. Its controller may draw up to two cards at the beginning of the next turn's upkeep.
You draw a card at the beginning of the next turn's upkeep.

Sly Instigator

{U}, {T}: Until your next turn, target creature an opponent controls can't be blocked. Goad that creature. (Until your next turn, that creature attacks each combat if able and attacks a player other than you if able.)

Adarkar Valkyrie

Flying, vigilance
{T}: When target creature other than Adarkar Valkyrie dies this turn, return that card to the battlefield under your control.

False Orders

Cast this spell only during the declare blockers step.
Remove target creature defending player controls from combat. Creatures it was blocking that had become blocked by only that creature this combat become unblocked. You may have it block an attacking creature of your choice.

Deflecting Palm

The next time a source of your choice would deal damage to you this turn, prevent that damage. If damage is prevented this way, Deflecting Palm deals that much damage to that source's controller.

Ethereal Haze

Prevent all damage that would be dealt by creatures this turn.

Illusionist's Gambit

Cast this spell only during the declare blockers step on an opponent's turn.
Remove all attacking creatures from combat and untap them. After this phase, there is an additional combat phase. Each of those creatures attacks that combat if able. They can't attack you or planeswalkers you control that combat.

Kazuul, Tyrant of the Cliffs

Whenever a creature an opponent controls attacks, if you're the defending player, create a 3/3 red Ogre creature token unless that creature's controller pays {3}.

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.

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.

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.

Duelist's Heritage

Whenever one or more creatures attack, you may have target attacking creature gain double strike until end of turn.

Mangara, the Diplomat

Lifelink
Whenever an opponent attacks with creatures, if two or more of those creatures are attacking you and/or planeswalkers you control, draw a card.
Whenever an opponent casts their second spell each turn, draw a card.

Comeuppance

Prevent all damage that would be dealt to you and planeswalkers you control this turn by sources you don't control. If damage from a creature source is prevented this way, Comeuppance deals that much damage to that creature. If damage from a noncreature source is prevented this way, Comeuppance deals that much damage to the source's controller.

Leyline of Anticipation

If Leyline of Anticipation is in your opening hand, you may begin the game with it on the battlefield.
You may cast spells as though they had flash.