Draw X cards, then discard X cards. Create a 1/1 white Spirit creature token with flying for each card type among cards discarded this way.

When Octo Opus enters the battlefield, create a 4/4 blue Octopus Performer creature token named Contortionist with "At the beginning of your upkeep, you may fold this token in half." (It becomes 2/2, then 1/1, ½/½, and so on.)

Sacrifice Octo Opus: Draw a card and an additional card for each of Contortionist's folds.

Enchant creature

Enchanted creature has base power and toughness 8/8 and has "Whenever this creature attacks, you may tap target creature with power 8 or less."

Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

At the beginning of combat on your turn, exile target red, white, or black creature card from your graveyard. Create a token that's a copy of that card, except it's 1/1. It gains haste until your next turn.

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

Whenever you cast an instant spell from your hand, it gains rebound. (Exile it as it resolves. At the beginning of your next upkeep, you may cast it from exile without paying its mana cost.)

When Ojer Pakpatiq dies, return it to the battlefield tapped and transformed under its owner's control with three time counters on it.

Whenever you cast a noncreature spell, choose one —

• Tap target creature.

• Ojutai Exemplars gains first strike and lifelink until end of turn.

• Exile Ojutai Exemplars, then return it to the battlefield tapped under its owner's control.

: Add .

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

Creatures you control have base power and toughness 3/3 until end of turn. You may search your library and/or graveyard for a card named Oko, the Trickster, reveal it, and put it into your hand. If you search your library this way, shuffle.

Trample

Whenever Oliphaunt attacks, another target creature you control gets +2/+0 and gains trample until end of turn.

Mountaincycling (, Discard this card: Search your library for a Mountain card, reveal it, put it into your hand, then shuffle.)

When Omenpath Journey enters the battlefield, search your library for up to five land cards that have different names, exile them, then shuffle.

At the beginning of your end step, choose a card at random exiled with Omenpath Journey and put it onto the battlefield tapped.

When Omenspeaker enters the battlefield, scry 2. (Look at the top two cards of your library, then put any number of them on the bottom of your library and the rest on top in any order.)

Flying

Whenever you cycle or discard a card, target creature an opponent controls gets -2/-0 until end of turn.

Creatures can't attack planeswalkers you control unless their controller pays for each creature they control that's attacking a planeswalker you control.

, Exile Onakke Oathkeeper from your graveyard: Return target planeswalker card from your graveyard to the battlefield.

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

At the beginning of each upkeep, if a player cast two or more spells last turn, transform One of the Pack.

Flying

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

Enchant creature

At the beginning of your upkeep, sacrifice a creature.

Enchanted creature gets +3/+3 and has trample.

Enchanted creature is a Demon Spirit.

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 the battlefield 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 the battlefield 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 the battlefield, 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."

More Than Meets the Eye (You may cast this card converted for .)

At the beginning of each end step, bolster 1. (Choose a creature with the least toughness among creatures you control and put a +1/+1 counter on it.)

When Optimus Prime dies, return it to the battlefield converted under its owner's control.

Lifelink

Whenever Orah, Skyclave Hierophant or another Cleric you control dies, return target Cleric card with lesser mana value from your graveyard to the battlefield.

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

Orcish Conscripts can't attack unless at least two other creatures attack.

Orcish Conscripts can't block unless at least two other creatures block.

: Look at the top three cards of target player's library.

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.

When this creature enters the battlefield, you may exile target non-Horse creature you control that wasn't put onto the battlefield with this ability this turn, then return it to the battlefield under its owner's control.

, , 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.

Flying, lifelink, indestructible, haste

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

: Add .

As long as Orochi Merge-Keeper is modified, it has ": Add ." (Equipment, Auras you control, and counters are modifications.)