First strike

Landfall — Whenever a land you control enters, Ondu Greathorn gets +2/+2 until end of turn.

Lifelink

Whenever another modified creature you control dies, put two +1/+1 counters on Ondu Knotmaster.

Ondu Skyruins enters tapped.

: Add .

Cohort — , Tap an untapped Ally you control: You gain 2 life.

Spree (Choose one or more additional costs.)

+ — Return target creature card from your graveyard to the battlefield.

+ — Return target Mount or Vehicle card from your graveyard to the battlefield.

+ — Return target Aura or Equipment card from your graveyard to the battlefield attached to a creature you control.

(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.

You lose the game.

Discard your hand.

Draw cards equal to the highest mana value among artifacts you control.

Enchant creature or enchantment

Enchanted permanent is an enchantment and loses all other card types. (It still has its abilities, but it's no longer a creature.)

: Target Robot gets +2/+0 until end of turn.

Flying

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

Haste

At the beginning of your upkeep, return a red creature you control to its owner's hand.

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 Onulet dies, you gain 2 life.

: Target player loses 1 life.

Whenever a player casts a black spell, you may pay . If you do, untap target permanent.

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.

Target player draws a card.

Retrace (You may cast this card from your graveyard by discarding a land card in addition to paying its other costs.)

, Remove one or more +1/+1 counters from among creatures you control: Create an X/X green Ooze creature token, where X is the number of +1/+1 counters removed this way.

Whenever an opponent casts a creature spell, if Opal Acrolith is an enchantment, Opal Acrolith becomes a 2/4 Soldier creature.

: Opal Acrolith becomes an enchantment.

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 Champion is an enchantment, Opal Champion becomes a 3/3 Knight creature with first strike.

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.

: Add .

, : Add one mana of any color in your commander's color identity. If you spend this mana to cast your commander, it enters with a number of additional +1/+1 counters on it equal to the number of times it's been cast from the command zone this game.

Each other non-Aura enchantment is a creature in addition to its other types and has base power and base toughness each equal to its mana value.

Sunburst (This enters with a charge counter on it for each color of mana spent to cast it.)

Equipped creature gets +X/+X, where X is the number of charge counters on Opaline Bracers.

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

: Add one mana of any color.

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."

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

Choose one —

• Add two mana of any one color and two mana of any other color. Spend this mana only to cast creature or enchantment spells.

• Creatures you control get +1/+0 until end of turn.

X can't be greater than the number of players in the game.

Reveal cards from the top of your library until you reveal X land cards. Put those land cards onto the battlefield tapped and the rest on the bottom of your library in a random order.

Whenever Ophidian attacks and isn't blocked, you may draw a card. If you do, Ophidian assigns no combat damage this turn.

At the beginning of each upkeep, if you control no Snakes, create a 1/1 black Snake creature token with deathtouch.

Flying

When Opportunistic Dragon enters, choose target Human or artifact an opponent controls. For as long as Opportunistic Dragon remains on the battlefield, gain control of that permanent, it loses all abilities, and it can't attack or block.

Tap an untapped creature you control: Tap target artifact, creature, or land.

Whenever a player casts a spell, that player discards a card.

Counter target spell unless its controller pays for each card in your hand.

Whenever you crank Optical Optimizer, until end of turn, target creature becomes an artifact in addition to its other types and gains ": Draw a card."

Living metal (During your turn, this Vehicle is also a creature.)

Trample

Whenever you attack, bolster 2. The chosen creature gains trample until end of turn. When that creature deals combat damage to a player this turn, convert Optimus Prime.

Opulent Palace enters tapped.

: Add , , or .

Haste

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

When Oracle of Bones enters, if tribute wasn't paid, you may cast an instant or sorcery spell from your hand without paying its mana cost.

You may play an additional land on each of your turns.

Play with the top card of your library revealed.

You may play lands from the top of your library.

Flying

When Oracle of the Alpha enters the battlefield, conjure the Power Nine into your library, then shuffle.

Whenever Oracle of the Alpha attacks, scry 1.

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

, : 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.

Trample

Landfall — Whenever a land you control enters, put a +1/+1 counter on Oran-Rief Hydra. If that land is a Forest, put two +1/+1 counters on Oran-Rief Hydra instead.

When Oran-Rief Ooze enters, put a +1/+1 counter on target creature you control.

Whenever Oran-Rief Ooze attacks, put a +1/+1 counter on each attacking creature with a +1/+1 counter on it.

Whenever Oran-Rief Survivalist or another Ally you control enters, you may put a +1/+1 counter on Oran-Rief Survivalist.

As an additional cost to cast this spell, you may reveal a Dragon card from your hand.

Defender, flying

When Orator of Ojutai enters, if you revealed a Dragon card or controlled a Dragon as you cast this spell, draw a card.