Narset, Enlightened Master

First strike, hexproof
Whenever Narset, Enlightened Master attacks, exile the top four cards of your library. Until end of turn, you may cast noncreature spells from among those cards without paying their mana costs.

Shock

Akroan Horse

Defender
When Akroan Horse enters, an opponent gains control of it.
At the beginning of your upkeep, each opponent creates a 1/1 white Soldier creature token.

Become Immense

Delve (Each card you exile from your graveyard while casting this spell pays for {1}.)
Target creature gets +6/+6 until end of turn.

Shifting Loyalties

Exchange control of two target permanents that share a card type. (Artifact, creature, enchantment, land, and planeswalker are card types.)

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.)

Goryo's Vengeance

Return target legendary creature card from your graveyard to the battlefield. That creature gains haste. Exile it at the beginning of the next end step.
Splice onto Arcane {2}{B} (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.)

Swamp

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Omniscience

You may cast spells from your hand without paying their mana costs.

Lich's Mirror

If you would lose the game, instead shuffle your hand, your graveyard, and all permanents you own into your library, then draw seven cards and your life total becomes 20.