Flying, lifelink

Whenever one or more outlaws you control deal combat damage to a player, create a Treasure token. (Assassins, Mercenaries, Pirates, Rogues, and Warlocks are outlaws.)

, Sacrifice two Treasures: Put two +1/+1 counters on each creature you control. Activate only as a sorcery.

Flying

Olivia's Bloodsworn can't block.

: Target Vampire gains haste until end of turn.

Target creature gets -2/-2 until end of turn. If it's night, that creature gets -13/-13 until end of turn instead.

Whenever you cast a creature spell, choose one —

• Create a 1/1 colorless Gnome artifact creature token.

• Create a token that's a copy of target artifact token you control.

When Ominous Traveler enters the battlefield, draft a card from Ominous Traveler's spellbook. That card perpetually gains "You may spend mana as though it were mana of any color to cast this spell" and "When you cast this spell, return a creature named Ominous Traveler you control to its owner's hand."

Whenever Omo, Queen of Vesuva enters or attacks, put an everything counter on each of up to one target land and up to one target creature.

Each land with an everything counter on it is every land type in addition to its other types.

Each nonland creature with an everything counter on it is every creature type.

Reach

: Onakke Javelineer deals 2 damage to target player or battle.

You may look at the top card of your library any time.

You may play lands and cast spells from the top of your library.

Once during each of your turns, you may cast a spell from your hand or the top of your library without paying its mana cost.

Whenever one or more artifacts you control leave the battlefield during your turn, create a 1/1 colorless Construct artifact creature token. This ability triggers only once each turn.

, Sacrifice an artifact: Oni-Cult Anvil deals 1 damage to each opponent. You gain 1 life.

When you have 10 or less life, if Opal Avenger is an enchantment, Opal Avenger becomes a 3/5 Soldier creature.

Whenever a nontoken creature you control dies, create a 2/2 black Zombie creature token.

Enchant creature

Enchanted creature can't attack or block unless its controller pays .

Activated abilities of enchanted creature cost more to activate.

Eerie — Whenever an enchantment you control enters and whenever you fully unlock a Room, put a +1/+1 counter on target creature.

, : Exile the top card of your library. Until end of turn, you may play that card. Put a brick counter on Oracle's Vault.

: Exile the top card of your library. Until end of turn, you may play that card without paying its mana cost. Activate only if there are three or more brick counters on Oracle's Vault.

: Oran-Rief Invoker gets +5/+5 and gains trample until end of turn.

Oran-Rief, the Vastwood enters tapped.

: Add .

: Put a +1/+1 counter on each green creature that entered this turn.

, Sacrifice an artifact: Orcish Vandal deals 2 damage to any target.

Battalion — Whenever Ordruun Veteran and at least two other creatures attack, Ordruun Veteran gains double strike until end of turn. (It deals both first-strike and regular combat damage.)

Flying

If you would draw a card while your library has no cards in it, instead put five +1/+1 counters on Ormos, Archive Keeper.

, Discard three cards with different names: Draw five cards.

Flying

Whenever Oros, the Avenger deals combat damage to a player, you may pay . If you do, Oros deals 3 damage to each nonwhite creature.

Changeling

Whenever you cast an instant or sorcery spell, if it targets one or more other permanents you control, create a token that's a copy of one of those permanents.

When a spell or ability an opponent controls causes you to discard this card, create a token that's a copy of target permanent.

Orzhov Basilica enters tapped.

When Orzhov Basilica enters, return a land you control to its owner's hand.

: Add .

: Add or .

, , Sacrifice Orzhov Cluestone: Draw a card.

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

When Orzhov Euthanist enters or the creature it haunts dies, destroy target creature that was dealt damage this turn.

: Target player gains 1 life.

: Each player loses 1 life.

: Add or .

, , Sacrifice Orzhov Locket: Draw two cards.

Whenever Orzhov Racketeers deals combat damage to a player, that player discards a card.

Afterlife 2 (When this creature dies, create two 1/1 white and black Spirit creature tokens with flying.)

: Add .

, : Target player loses 1 life and you gain 1 life.

Flying

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

, Sacrifice Ouphe Vandals: Counter target activated ability from an artifact source and destroy that artifact if it's on the battlefield. (Mana abilities can't be targeted.)

X target blocked creatures assign their combat damage this turn as though they weren't blocked.

Trample, haste

Crew 1 (Tap any number of creatures you control with total power 1 or more: This Vehicle becomes an artifact creature until end of turn.)

Choose one —

• Destroy target artifact or enchantment.

• Target creature you control explores, then it explores again. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on that creature, then put the card back or put it into your graveyard. Then repeat this process.)

Whenever a player taps a land for mana, that player adds one mana of any type that land produced, and Overabundance deals 1 damage to the player.

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 (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.)

Flash

Flying

Exploit (When this creature enters, you may sacrifice a creature.)

When Overcharged Amalgam exploits a creature, counter target spell, activated ability, or triggered ability.

Creatures you control get +2/+2 and gain trample until end of turn. (Each of those creatures can deal excess combat damage to the player or planeswalker it's attacking.)

Enchant opponent

When Overencumbered enters, enchanted opponent creates a Clue token, a Food token, and a Junk token.

At the beginning of combat on enchanted opponent's turn, that player may pay for each artifact they control. If they don't, creatures can't attack this combat.

Target player draws seven cards.

Enrage — Whenever Overgrown Armasaur is dealt damage, create a 1/1 green Saproling creature token.

Sacrifice a land: You gain 3 life.

When Overgrown Pest enters, look at the top five cards of your library. You may reveal a land or double-faced card from among them and put that card into your hand. Put the rest on the bottom of your library in a random order.

: Add one mana of any color.

: Add two mana of any one color. Spend this mana only to turn permanents face up.

When Overgrowth Elemental enters, put a +1/+1 counter on another target Elemental you control.

Whenever another creature you control dies, you gain 1 life. If that creature was an Elemental, put a +1/+1 counter on Overgrowth Elemental.

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

Destroy target artifact if its mana value is 2 or less. If this spell was kicked, destroy that artifact if its mana value is 5 or less instead.

Impending 5— (If you cast this spell for its impending cost, it enters with five time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)

Whenever Overlord of the Balemurk enters or attacks, mill four cards, then you may return a non-Avatar creature card or a planeswalker card from your graveyard to your hand.

Impending 4— (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)

Flying

Whenever Overlord of the Floodpits enters or attacks, draw two cards, then discard a card.

Impending 4— (If you cast this spell for its impending cost, it enters with four time counters and isn't a creature until the last is removed. At the beginning of your end step, remove a time counter from it.)

Whenever Overlord of the Mistmoors enters or attacks, create two 2/1 white Insect creature tokens with flying.

Freerunning (You may cast this spell for its freerunning cost if you dealt combat damage to a player this turn with an Assassin or commander.)

Untap all creatures you control that attacked this turn. If it's your main phase, there is an additional combat phase after this phase, followed by an additional main phase.

Counter target spell unless its controller pays for each artifact you control.