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.

O-Kagachi Made Manifest is all colors.

Flying, trample

Whenever O-Kagachi Made Manifest attacks, defending player chooses a nonland card in your graveyard. Return that card to your hand. O-Kagachi Made Manifest gets +X/+0 until end of turn, where X is the mana value of that card.

You may exert Oketra's Avenger as it attacks. When you do, prevent all combat damage that would be dealt to it this turn. (An exerted creature won't untap during your next untap step.)

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.

: Add .

, : Target legendary creature gets +1/+1 until end of turn.

As this creature transforms into Olag, Ludevic's Hubris, it becomes a copy of a creature card exiled with it, except its name is Olag, Ludevic's Hubris, it's 4/4, and it's a legendary blue and black Zombie in addition to its other colors and types. Put a number of +1/+1 counters on Olag equal to the number of creature cards exiled with it.

Phasing, cumulative upkeep , echo , fading 3, bands with other Dinosaurs, protection from Homarids, snow-covered plainswalk, flanking, rampage 2

Flying

Whenever a creature you control deals combat damage to a player, create that many Treasure tokens.

When you cast this spell, reveal cards from the top of your library until you reveal X creature cards. Put all creature cards revealed this way into your graveyard, then put the rest on the bottom of your library in a random order.

Old Stickfingers's power and toughness are each equal to the number of creature cards in your graveyard.

Trample

When Old-Growth Troll dies, if it was a creature, return it to the battlefield. It's an Aura enchantment with enchant Forest you control and "Enchanted Forest has ‘: Add ' and ‘, , Sacrifice this land: Create a tapped 4/4 green Troll Warrior creature token with trample.'"

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

Each opponent exiles a creature with the greatest power among creatures that player controls.

Spell mastery — If there are two or more instant and/or sorcery cards in your graveyard, Olórin's Searing Light deals damage to each opponent equal to the power of the creature they exiled.

When Oltec Archaeologists enters the battlefield, choose one —

• Return target artifact card from your graveyard to your hand.

• Scry 3. (Look at the top three cards of your library, then put any number of them on the bottom and the rest on top in any order.)

Omarthis, Ghostfire Initiate enters the battlefield 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.

Flash

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

, Sacrifice Omen of the Forge: Scry 2.

Landfall — Whenever a land enters the battlefield under your control, 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.

O-Naginata can be attached only to a creature with power 3 or greater.

Equipped creature gets +3/+0 and has trample.

Equip (: Attach to target creature you control. Equip only as a sorcery.)

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.

First strike

Landfall — Whenever a land enters the battlefield under your control, Ondu Greathorn gets +2/+2 until end of turn.

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

I — The Ring tempts you, then each player mills cards equal to your Ring-bearer's power.

II — Destroy all nonlegendary creatures.

III — Each opponent loses 1 life for each creature card in that player's graveyard.

Flying

Whenever you draw a card, put a +1/+1 counter on Oneirophage.

Whenever you cast a creature spell, tap target creature.

: Target creature you control gains deathtouch until end of turn. (Any amount of damage it deals to a creature is enough to destroy it.)

Defender, flying

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

, Sacrifice a non-Ooze creature: Create an X/X green Ooze creature token, where X is the sacrificed creature's power. Activate only as a sorcery.

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

When an opponent casts a creature spell, if Opal Guardian is an enchantment, Opal Guardian becomes a 3/4 Gargoyle creature with flying and protection from red.

Search your library for a basic land card or Gate card, reveal it, put it into your hand, then shuffle.

Add . You may open a sealed Magic booster pack. Until end of turn, you may cast spells from among the cards in that booster pack.

Flash

You control your opponents while they're searching their libraries.

While an opponent is searching their library, they exile each card they find. You may play those cards for as long as they remain exiled, and you may spend mana as though it were mana of any color to cast them.

Enchant creature

Enchanted creature has ": Scry 1, then draw a card." (To scry 1, look at the top card of your library, then you may put that card on the bottom of your library.)

You have hexproof. (You can't be the target of spells or abilities your opponents control.)

If a creature would deal damage to you, prevent 1 of that damage.

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.

Flying

Order of Midnight can't block.

Fear (This creature can't be blocked except by artifact creatures and/or black creatures.)

Whenever Order of Yawgmoth deals damage to a player, that player discards a card.

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

Inspired — Whenever Oreskos Sun Guide becomes untapped, you gain 2 life.

Your team may sacrifice any number of creatures. For each creature sacrificed this way, you add .

Improvise (Your artifacts can help cast this spell. Each artifact you tap after you're done activating mana abilities pays for .)

Destroy all nonartifact creatures.

, , 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.

: 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.

Whenever Ornery Goblin blocks or becomes blocked by a creature, Ornery Goblin deals 1 damage to that creature.

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

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

Orzhov Guildgate enters the battlefield tapped.

: Add or .

, : Add .

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.")

: 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.