msem-instigator

Motley — At the beginning of combat on your turn, if there are five or more names among nonland permanents you control, Ochre Knight gets +2/+1 until end of turn and you gain 1 life.

{T}: You may put a land card from your hand onto the battlefield.
{1}, {T}: Aetherize target land you control. (To aetherize, create a token that's a copy of it, then exile that token.)

When Old Salt enters, forebode. (Create a tapped colorless Omen artifact token with “{T}, Discard a card, Sacrifice this artifact: Draw a card.”)

Whenever you cast an instant or sorcery spell from your hand, you may cast target card with the same name as that spell from your graveyard. (You still pay its costs.)

Whenever you attack with one or more Pirates, create that many 1/1 white Bird creature tokens with flying that are tapped and attacking. At end of combat, choose one of those tokens, then exile the rest.

When Olten Surveyor enters, choose any number. Each opponent creates a 1/1 colorless Servo artifact creature token for each mode chosen.
• Destroy target artifact or enchantment with mana value 3 or less.
• Shuffle up to four cards from target player's graveyard into their library.
• You gain 4 life.

When Ominous Presence enters, search your library for a Curse card, reveal it, then shuffle. If it has mana value 4 or less, you may put it onto the battlefield. Otherwise, put it into your hand.
Ominous Presence gets +1/+1 for each Curse attached to your opponents.

When Ontarachie Envoy enters, nourish, then germinate. (To nourish, put a +1/+1 counter on this creature or create a 1/1 white Citizen creature token. To germinate, put a +1/+1 counter on a creature you control or create a 1/1 green Saproling creature token.)

Whenever Ontarachie Hunter attacks, each opponent loses 1 life.
At the beginning of your end step, if an opponent has 10 or less life, transform Ontarachie Hunter.

Deathtouch
Whenever Oozing Adder attacks, you may have target creature defending player controls block it this combat if able.

When Ophorio Scavenger enters, create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)
Ophorio Scavenger gets +1/+1 as long as you control three or more artifacts.

When Opulent Proprietor enters, you may search your library and/or graveyard for an Aura, Aurashaper, Equipment, or Vehicle card, reveal it, and put it into your hand. If you search your library this way, shuffle.

When Oracle of Edicts enters, adjudicate. (Create a white Aura enchantment token with enchant creature and “Sacrifice this token: Untap enchanted creature” attached to target creature.)
Whenever an Aura you control enters, scry 1.

Whenever Oracle of Flames becomes tapped, up to one target creature you control gets +2/-2 until end of turn.

Whenever you cast a spell during an opponent's turn, put a +1/+1 counter on Oracle of Tides.

Menace
At the beginning of your end step, if a player lost 3 or more life this turn, put a +1/+1 counter on target Azra or Demon you control.

Ward—Pay 2 life.
When Orchid Suit enters, target opponent reveals their hand, then exiles a nonland card of their choice from it until Orchid Suit leaves the battlefield.

Whenever Organ Scavenger perseveres, each opponent loses 2 life. (A creature perseveres when it survives damage.)

Each instant and sorcery card in your hand has cycling {2}. ({2}, Discard this card: Draw a card.)
At the beginning of your end step, if there are four or more instant and/or sorcery cards in your graveyard, you may pay {1}{U/R}. If you do, return an instant or sorcery card at random from your graveyard to your hand.

Your opponents play with the top card of their library revealed.
Your opponents can't cast spells during your turn.
You may play lands and cast spells from the top of an opponent's library during your turn.

Defender
Whenever another creature you control enters, Orphan of the Nav gets +1/+1 until end of turn and can attack as though it didn't have defender this turn.

When Oshiruko Purifier enters, create a 2/2 colorless Spirit creature token.
Colorless creatures you control have lifelink.

Oshiruko Whisperwalker can't be blocked except by Rogues.
Whenever a creature is returned to its owner's hand, you may draw a card. If you do, discard a card.

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)

Distorted (This creature can be blocked by tapped creatures but not untapped creatures.)
Oslyd Heretic gets +1/+1 as long as you control no other creatures.