Tap four untapped creatures you control: Destroy target artifact or enchantment.

Bushido 2 (Whenever this creature blocks or becomes blocked, it gets +2/+2 until end of turn.)

, Pay 5 life: Regenerate Numai Outcast.

Enchant artifact or creature

Enchanted permanent doesn't untap during its controller's untap step.

At the beginning of the upkeep of enchanted permanent's controller, that player loses 1 life.

Flying

Whenever Numot, the Devastator deals combat damage to a player, you may pay . If you do, destroy up to two target lands.

When Nylea's Huntmaster enters, target creature you control gets +X/+0 until end of turn, where X is your devotion to green. (Each in the mana costs of permanents you control counts toward your devotion to green.)

Trample

If you tap a permanent for mana, it produces three times as much of that mana instead.

At the beginning of your upkeep, you gain 1 life.

This spell costs less to cast if an opponent controls a green permanent.

Deathtouch

Whenever Oakhame Adversary deals combat damage to a player, draw a card.

Whenever you lose life, for each 1 life you lost, sacrifice a permanent other than Oath of Lim-Dûl unless you discard a card. <I>(Damage dealt to you causes you to lose life.)</I>

: Draw a card.

Oathsworn Vampire enters tapped.

You may cast Oathsworn Vampire from your graveyard if you gained life this turn.

Choose one —

• Return target multicolored permanent card with mana value 3 or less from your graveyard to the battlefield tapped.

• Counter target instant or sorcery spell.

• Destroy target creature or planeswalker with mana value 3 or less.

If it's neither day nor night, it becomes day as Obsessive Astronomer enters.

Whenever day becomes night or night becomes day, discard up to two cards, then draw that many cards.

This spell costs less to cast for each land your opponents control that could produce .

Flying

When Obsidian Charmaw enters, destroy target nonbasic land an opponent controls.

At the beginning of combat on your turn, up to one target land you control becomes an X/X Elemental creature with trample and haste until end of turn, where X is Obuun's power. It's still a land.

Landfall — Whenever a land you control enters, put a +1/+1 counter on target creature.

Gift an Octopus (You may promise an opponent a gift as you cast this spell. If you do, when it enters, they create an 8/8 blue Octopus creature token.)

At the beginning of each end step, create a token that's a copy of target creature token that entered the battlefield this turn.

At the beginning of each combat, creatures you control gain banding until end of turn if a creature you control has banding. The same is true for changeling, devoid, fear, flanking, horsemanship, ingest, intimidate, landwalk, shroud, tantrum, wither, and the activated ability "Sacrifice this creature: Add ."

First strike (This creature deals combat damage before creatures without first strike.)

Whenever Odric, Master Tactician and at least three other creatures attack, you choose which creatures block this combat and how those creatures block.

Target creature gains deathtouch and indestructible until end of turn. (Damage and effects that say "destroy" don't destroy it.)

Infect (This creature deals damage to creatures in the form of -1/-1 counters and to players in the form of poison counters.)

: Ogre Menial gets +1/+0 until end of turn.

Whenever another nontoken creature dies, you may create a 1/1 black Rat creature token.

Rats you control have deathtouch.

Equipped creature gets +2/+2.

Whenever Ogre-Head Helm or equipped creature deals combat damage to a player, you may sacrifice it. If you do, discard your hand, then draw three cards.

Reconfigure (: Attach to target creature you control; or unattach from a creature. Reconfigure only as a sorcery. While attached, this isn't a creature.)

Trample

Whenever Ojer Kaslem deals combat damage to a player, reveal that many cards from the top of your library. You may put a creature card and/or a land card from among them onto the battlefield. Put the rest on the bottom in a random order.

When Ojer Kaslem dies, return it to the battlefield tapped and transformed under its owner's control.

: Add or .

: Ojutai Monument becomes a 4/4 white and blue Dragon artifact creature with flying until end of turn.

Create a 2/2 blue Djinn Monk creature token with flying.

Rebound (If you cast this spell from your hand, exile it as it resolves. At the beginning of your next upkeep, you may cast this card from exile without paying its mana cost.)

Flying, trample

Whenever O-Kagachi, Vengeful Kami deals combat damage to a player, if that player attacked you during their last turn, exile target nonland permanent that player controls.

White creature spells you cast cost less to cast.

Whenever you cast a creature spell, create a 1/1 white Warrior creature token with vigilance.

Flying

Old Man Willow's power and toughness are each equal to the number of lands you control.

Whenever Old Man Willow attacks, you may sacrifice another creature or a token. When you do, target creature an opponent controls gets -2/-2 until end of turn.

Flying, haste

Whenever Olivia, Crimson Bride attacks, return target creature card from your graveyard to the battlefield tapped and attacking. It gains "When you don't control a legendary Vampire, exile this creature."

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

Omarthis, Ghostfire Initiate enters with X +1/+1 counters on it.

Whenever you put one or more +1/+1 counters on another colorless creature, you may put a +1/+1 counter on Omarthis.

When Omarthis dies, manifest a number of cards from the top of your library equal to the number of counters on it.

Look at the top three cards of your library, then put them back in any order. You may shuffle.

Draw a card.

Players can't draw cards.

At the beginning of each player's draw step, that player exiles the top card of their library. If it's a land card, the player puts it onto the battlefield. Otherwise, the player casts it without paying its mana cost if able.

Flash

When Omen of the Dead enters, return target creature card from your graveyard to your hand.

, Sacrifice Omen of the Dead: Scry 2.

Flash

When Omen of the Hunt enters, you may search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

, Sacrifice Omen of the Hunt: Scry 2.

Flash

When Omen of the Sun enters, create two 1/1 white Human Soldier creature tokens and you gain 2 life.

, Sacrifice Omen of the Sun: Scry 2.

Vanishing 4 (This land enters the battlefield with four time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)

: Add , , or .

When Omenspeaker enters, 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.)

, , Sacrifice Ominous Parcel: Search your library for a basic land card, reveal it, put it into your hand, then shuffle.

, , Sacrifice Ominous Parcel: It deals 4 damage to target creature.

Whenever you draw a card, put a foreshadow counter on Ominous Seas.

Remove eight foreshadow counters from Ominous Seas: Create an 8/8 blue Kraken creature token.

Cycling (, Discard this card: Draw a card.)

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."

When Omnath, Locus of Creation enters, draw a card.

Landfall — Whenever a land you control enters, you gain 4 life if this is the first time this ability has resolved this turn. If it's the second time, add . If it's the third time, Omnath deals 4 damage to each opponent and each planeswalker you don't control.

Landfall — Whenever a land you control enters, create a 5/5 red and green Elemental creature token.

Whenever Omnath, Locus of Rage or another Elemental you control dies, Omnath deals 3 damage to any target.

: Target creature becomes a Frog with base power and toughness 3/3 until end of turn.

Changeling

Omnipresent Impostor has all card names.

As you search your library for one or more cards, you may choose Omnipresent Impostor as one of those cards. (For example, if you search for two land cards, you may find Omnipresent Impostor and a land card.)

, : You may cast an instant or sorcery spell from your hand without paying its mana cost.

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.

Exile all permanents and all cards from all graveyards. Each player shuffles their hand into their library, then draws seven cards. Each player's life total becomes 10. Exile Once More with Feeling.

DCI ruling — A deck can have only one card named Once More with Feeling.

Rally — Whenever Ondu Champion or another Ally you control enters, creatures you control gain trample until end of turn.