Domain — Create a 1/1 blue Bird creature token with flying for each basic land type among lands you control.

When this creature enters, you may exile target non-Horse creature you control that wasn't put onto the battlefield with this ability this turn, then return it to the battlefield under its owner's control.

Mentor (Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)

Whenever you attack a player, target creature that's attacking that player gains first strike until end of turn.

Whenever you cast a Spirit or Arcane spell, you may destroy target nonbasic land.

: Add . Spend this mana only to cast an instant or sorcery spell.

Craft with four or more red instant and/or sorcery cards (, Exile this artifact, Exile the four or more from your graveyard: Return this card transformed under its owner's control. Craft only as a sorcery.)

When Oreskos Explorer enters, search your library for up to X Plains cards, where X is the number of players who control more lands than you. Reveal those cards, put them into your hand, then shuffle.

, Exile three cards from your graveyard: Target player loses 3 life.

When Organ Hoarder enters, look at the top three cards of your library, then put one of them into your hand and the rest into your graveyard.

Trample

Orgg can't attack if defending player controls an untapped creature with power 3 or greater.

Orgg can't block creatures with power 3 or greater.

, , Sacrifice Origin Spellbomb: Create a 1/1 colorless Myr artifact creature token.

When Origin Spellbomb is put into a graveyard from the battlefield, you may pay . If you do, draw a card.

Kicker (You may pay an additional as you cast this spell.)

Target player can't cast spells this turn. If this spell was kicked, creatures can't attack this turn.

Whenever one or more creatures attack you, you gain 1 life for each attacking creature.

Kicker (You may pay an additional as you cast this spell.)

Prevent the next 2 damage that would be dealt to any target this turn. If this spell was kicked, prevent the next 4 damage that would be dealt to that permanent or player this turn instead.

: Prevent all damage that would be dealt to target creature this turn.

Grandeur — Discard another card named Oriss, Samite Guardian: Target player can't cast spells this turn, and creatures that player controls can't attack this turn.

Flying, trample, lifelink

Sacrifice another creature: Draw a card.

Untap target creature. It gets +1/+3 until end of turn.

Deathtouch (Any amount of damage this deals to a creature is enough to destroy it.)

Whenever Ornery Dilophosaur attacks, if you control a creature with power 4 or greater, Ornery Dilophosaur gets +2/+2 until end of turn.

When Ornery Kudu enters, put a -1/-1 counter on target creature you control.

Flying

Tribute 2 (As this creature enters, an opponent of your choice may put two +1/+1 counters on it.)

When Ornitharch enters, if tribute wasn't paid, create two 1/1 white Bird creature tokens with flying.

, : Create a 1/1 green Snake creature token. If you control ten or more creatures, flip Orochi Eggwatcher.

: Add one mana of any color.

Whenever Orochi Ranger deals combat damage to a creature, tap that creature and it doesn't untap during its controller's next untap step.

: Add .

Whenever Orphans of the Wheat attacks, tap any number of untapped creatures you control. Orphans of the Wheat gets +1/+1 until end of turn for each creature tapped this way.

Vigilance

Orthodoxy Enforcer gets +2/+0 as long as you control two or more artifacts.

At the beginning of your upkeep, each player may put two +1/+1 counters on a creature they control. If a player does, creatures that player controls can't attack you or planeswalkers you control until your next turn.

Choose one —

• Return target creature you control and all Auras you control attached to it to their owner's hand.

• Destroy target creature and you lose life equal to its toughness.

• Return target creature card with mana value 1 or less from your graveyard to the battlefield.

Deathtouch

Afterlife 1 (When this creature dies, create a 1/1 white and black Spirit creature token with flying.)

Orzhov Guildgate enters tapped.

: Add or .

: Add or .

: Orzhov Keyrune becomes a 1/4 white and black Thrull artifact creature with lifelink until end of turn.

Haunt (When this creature dies, exile it haunting target creature.)

When Orzhov Pontiff enters or the creature it haunts dies, choose one —

• Creatures you control get +1/+1 until end of turn.

• Creatures you don't control get -1/-1 until end of turn.

, : Add .

Flying

At the beginning of each end step, if a creature died this turn, put a carrion counter on Osai Vultures.

Remove two carrion counters from Osai Vultures: Osai Vultures gets +1/+1 until end of turn.

When you cast this spell, create a token that's a copy of it, except it isn't legendary.

: Add . Spend this mana only to cast an artifact spell or activate an ability of an artifact.

Paradox — Whenever you cast a spell from anywhere other than your hand, investigate. (Create a Clue token. It's an artifact with ", Sacrifice this artifact: Draw a card.")

Lifelink

Delirium — At the beginning of your end step, if there are four or more card types among cards in your graveyard, each opponent may sacrifice a nonland permanent or discard a card. Then Osseous Sticktwister deals damage equal to its power to each opponent who didn't sacrifice a permanent or discard a card this way.

When Ossuary Rats enters, it deals X damage to target creature or planeswalker an opponent controls, where X is the number of creature cards in your graveyard.

, : Tap target creature.

Magical Tinkering — , , Sacrifice an artifact: Search your library for an artifact card with mana value equal to 1 plus the sacrificed artifact's mana value, put it onto the battlefield, then shuffle. Activate only as a sorcery.

: Add .

Channel — , Discard Otawara, Soaring City: Return target artifact, creature, enchantment, or planeswalker to its owner's hand. This ability costs less to activate for each legendary creature you control.

Flying

Whenever Oteclan Levitator attacks, target attacking creature without flying gains flying until end of turn.

Flying, lifelink, haste

Whenever Otharri, Suns' Glory attacks, you get an experience counter. Then create a 2/2 red Rebel creature token that's tapped and attacking for each experience counter you have.

, Tap an untapped Rebel you control: Return Otharri from your graveyard to the battlefield tapped.

Flash

When Otherworldly Escort dies, if it's not a Spirit, return it to the battlefield under its owner's control with four charge counters on it. It's a Spirit Detective. (It's no longer a Human.)

, , Remove a charge counter from Otherworldly Escort: Destroy target creature that dealt damage to you this turn.

Exile target creature. At the beginning of the next end step, return that card to the battlefield under its owner's control with a +1/+1 counter on it.

Mutate (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.)

Trample

Whenever this creature deals combat damage to a player, return target creature card with mutate from your graveyard to your hand.

When Oubliette enters, target creature phases out until Oubliette leaves the battlefield. Tap that creature as it phases in this way. (Auras and Equipment phase out with it. While permanents are phased out, they're treated as though they don't exist.)

Art rampage 2 (Whenever this creature becomes blocked by a creature, it gets +2/+2 for each creature in the blocker's art beyond the first.)

This spell can't be countered. (This includes by the ward ability.)

Tap up to two target creatures and put a stun counter on each of them. Investigate. (If a permanent with a stun counter would become untapped, remove one from it instead.)

Assist (Another player can pay up to of this spell's cost.)

Counter target spell.

This spell costs less to cast if it targets a green permanent.

Return target nonland permanent an opponent controls to its owner's hand.

Draw a card.

You may discard a Swamp card rather than pay this spell's mana cost.

Choose a creature type. All creatures of that type get -1/-1 until end of turn.