, : The next time a source of your choice would deal damage to you this turn, that damage is dealt to target creature of an opponent's choice instead.

Noxious Hatchling enters with four -1/-1 counters on it.

Wither (This deals damage to creatures in the form of -1/-1 counters.)

Whenever you cast a black spell, remove a -1/-1 counter from Noxious Hatchling.

Whenever you cast a green spell, remove a -1/-1 counter from Noxious Hatchling.

Choose one —

• Search your library for up to X land cards, reveal them, put them into your hand, then shuffle.

• Nylea's Intervention deals twice X damage to each creature with flying.

: Prevent the next 1 damage that would be dealt to target creature this turn.

When Oath of Kaya enters, it deals 3 damage to any target and you gain 3 life.

Whenever an opponent attacks a planeswalker you control with one or more creatures, Oath of Kaya deals 2 damage to that player and you gain 2 life.

At the beginning of each player's upkeep, that player chooses target player who has more life than they do and is their opponent. The first player may have Oath of Mages deal 1 damage to the second player.

Casualty X. The copy isn't legendary and has starting loyalty X. (As you cast this spell, you may sacrifice a creature with power X. When you do, copy this spell. The copy becomes a token.)

+1: Each opponent loses 2 life unless they discard a card. If you control a Demon or Devil, you gain 2 life.

−2: Create a 1/1 red Devil creature token with "When this creature dies, it deals 1 damage to any target."

−7: Target player draws seven cards and loses 7 life.

Menace

Whenever Obeka, Splitter of Seconds deals combat damage to a player, you get that many additional upkeep steps after this phase.

Reach

Whenever Obelisk Spider deals combat damage to a creature, put a -1/-1 counter on that creature.

Whenever you put one or more -1/-1 counters on a creature, each opponent loses 1 life and you gain 1 life.

Companion — Your starting deck contains only cards with odd mana values and land cards. (If this card is your chosen companion, you may put it into your hand from outside the game for as a sorcery.)

If a source you control with an odd mana value would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Flying, ward

Whenever Obsessive Collector deals combat damage to a player, seek a card with mana value equal to the number of cards in your hand.

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.

Ogre Enforcer can't be destroyed by lethal damage unless lethal damage dealt by a single source is marked on it.

, Discard a card at random: Ogre Shaman deals 2 damage to any target.

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.)

Attacking creatures you control have deathtouch.

Whenever a creature you control deals combat damage to a player, draw a card.

Trample

If a red source you control would deal an amount of noncombat damage less than Ojer Axonil's power to an opponent, that source deals damage equal to Ojer Axonil's power instead.

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

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.

Ninjutsu (, Return an unblocked attacker you control to hand: Put this card onto the battlefield from your hand tapped and attacking.)

Whenever Okiba-Gang Shinobi deals combat damage to a player, that player discards two cards.

When Ol' Buzzbark enters, roll X six-sided dice onto the battlefield from a height of at least X inches. For each die, put a number of +1/+1 counters equal to the result on each creature you control that die is touching. For each die, Ol' Buzzbark deals damage equal to the result to each creature an opponent controls that die is touching.

Flying

: Olivia Voldaren deals 1 damage to another target creature. That creature becomes a Vampire in addition to its other types. Put a +1/+1 counter on Olivia Voldaren.

: Gain control of target Vampire for as long as you control Olivia Voldaren.

Menace

Whenever Olivia's Attendants deals damage, create that many Blood tokens. (They're artifacts with ", , Discard a card, Sacrifice this artifact: Draw a card.")

: Olivia's Attendants deals 1 damage to any target.

Flash

When Omen of the Forge enters, it deals 2 damage to any target.

, Sacrifice Omen of the Forge: Scry 2.

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.

When Omnath, Locus of the Roil enters, it deals damage to any target equal to the number of Elementals you control.

Landfall — Whenever a land you control enters, put a +1/+1 counter on target Elemental you control. If you control eight or more lands, draw a card.

Enchant creature

Whenever enchanted creature deals combat damage to a player, you may search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

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.

Flying

Each other Rogue creature you control enters with an additional +1/+1 counter on it.

Whenever a creature you control with a +1/+1 counter on it deals combat damage to a player, that player discards a card.

Defender (This creature can't attack.)

Bushido 1 (Whenever this creature blocks or becomes blocked, it gets +1/+1 until end of turn.)

: The next time a source of your choice would deal damage this turn, that damage is dealt to Opal-Eye, Konda's Yojimbo instead.

: Prevent the next 1 damage that would be dealt to Opal-Eye this turn.

X target creatures can't be blocked this turn. Until end of turn, those creatures gain "Whenever this creature deals combat damage to a player, draw a card."

: Opportunist deals 1 damage to target creature that was dealt damage this turn.

: All damage that would be dealt to target creature this turn by a source of your choice is dealt to Oracle's Attendants instead.

Trample

Whenever another creature dies, put a +1/+1 counter on Orca, Siege Demon.

When Orca dies, it deals damage equal to its power divided as you choose among any number of targets.

, Sacrifice a creature: Orcish Bloodpainter deals 1 damage to any target.

Orcish Cannonade deals 2 damage to any target and 3 damage to you.

Draw a card.

Echo (At the beginning of your upkeep, if this came under your control since the beginning of your last upkeep, sacrifice it unless you pay its echo cost.)

When Orcish Hellraiser dies, it deals 2 damage to target player or planeswalker.

Enchant land

Orcish Mine enters with three ore counters on it.

At the beginning of your upkeep and whenever enchanted land becomes tapped, remove an ore counter from Orcish Mine.

When the last ore counter is removed from Orcish Mine, destroy enchanted land and Orcish Mine deals 2 damage to that land's controller.

Enchant creature

Whenever enchanted creature attacks, put a +1/+1 counter on it. Then if it has three or more +1/+1 counters on it, sacrifice Ordeal of Purphoros.

When you sacrifice Ordeal of Purphoros, it deals 3 damage to any target.

: Prevent the next 1 damage that would be dealt to Ordruun Commando this turn.

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)

I — Origin of the Hidden Ones deals 4 damage to any target.

II — Create two 1/1 black Assassin creature tokens with menace.

III — Whenever an Assassin you control attacks this turn, create a 1/1 black Assassin creature token with menace that's tapped and attacking.

If you control a Plains, you may tap an untapped creature you control rather than pay this spell's mana cost.

Prevent the next 4 damage that would be dealt to any target this turn.

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.

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.

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

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.

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.)

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.

Outflank deals damage to target attacking or blocking creature equal to the number of creatures you control.

At the beginning of your upkeep, choose one at random. Create a red and white creature token with those characteristics.

• 3/1 Human Warrior with trample and haste.

• 2/1 Human Cleric with lifelink and haste.

• 1/2 Human Rogue with haste and "When this creature enters, it deals 1 damage to any target."

Outnumber deals damage to target creature equal to the number of creatures you control.