msem-instigator

Observation Field enters with three charge counters on it.
{2}, {T}, Remove a charge counter from Observation Field: Draw a card and gain 2 life.
{T}, Sacrifice Observation Field: Shuffle any number of target cards from your graveyard into your library.

Trample
Ward {3} (Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays {3}.)
Cycling {2} ({2}, Discard this card: Draw a card.)

Flash
When Olten Vipermoa enters, you may return another creature you control to its owner's hand. If you do, put two +1/+1 counters on Olten Vipermoa.

At the beginning of your upkeep, create four 1/1 blue Elemental creature tokens with flying. You gain 4 life.
{2}{W}, Discard Olten's Farewell: Create two 1/1 blue Elemental creature tokens with flying. You gain 2 life.

{T}: Add {C}.
{6}, {T}, Discard a card: Search your library for a multicolored card, exile it, then shuffle. If its mana value is 3 or less, you may cast it without paying its mana cost. If you don't, put it into your hand. Activate only as a sorcery.

Rhapsody {5}{W}{W} (Pay {5}{W}{W} to cast this as a 4/4, or as a sorcery to make it become a 4/4.)
Whenever Oltenen Paradise-Seeker attacks, up to one target creature's base power and toughness each become equal to Oltenen Paradise-Seeker's power and toughness until end of turn.

Reach
When Oltenen Terror enters, crystallize. (Put a +1/+1 counter on a creature you control or create a Treasure.)
{1}{G}, Sacrifice an artifact or creature: Tap Oltenen Terror. It gains indestructible until end of turn.

Colossal 3—{5}{U} (You may cast this for its colossal cost to have it enter with three +1/+1 counters; or pay {5}{U} as a sorcery: Put three +1/+1 counters on it if it has none.)
When Omendiver's colossal ability puts one or more counters on it, scry 3.

Ominous Quag enters tapped.
{T}: Add {W} or {B}.
{2}{W}{B}, {T}, Sacrifice Ominous Quag: Draw a card.

Exile target creature or enchantment you control, then return that card to the battlefield under your control.
You may cast On Repeat from your graveyard any time you could cast a sorcery by discarding a land card in addition to paying its other costs.

Choose one or both —
• Put a +1/+1 counter on each of up to two target creatures.
• Put a +1/+1 counter on up to one target Elemental and up to one target Soldier.

Search your library for a creature or sorcery card, put it into your graveyard, then shuffle.
Reconstruct {2}{B} (You may cast this from your graveyard for its reconstruct cost reduced by the mana value of a permanent you sacrifice as you cast it this way. Then exile this.)

Lifelink
Whenever Operative BABY attacks or you cast a black or red spell, create a 1/1 blue Elemental creature token with flying.

Menace
Whenever Operative GINGER attacks or you cast a blue or white spell, Operative GINGER deals 1 damage to any target.

Flash
Whenever Operative POSH attacks or you cast a green or red spell, exile up to one target nontoken permanent. Return that card to the battlefield under its owner's control at the beginning of the next end step.

Deathtouch
Whenever Operative SCARY attacks or you cast a green or white spell, you may draw a card. If you do, you lose 2 life.

Ward {3}
Whenever Operative SPORTY attacks or you cast a blue or black spell, put a +1/+1 counter on Operative SPORTY.

Chronicle (As this enters and after your draw step, add a lore counter. Stop after III.)
[Lore I-II] You may discard a card. If you do, draw a card.
[Lore III] Create a token that's a copy of another target creature you control, except it has haste. Sacrifice it at the beginning of the next end step.

Oreskos Warden has lifelink as long as you control an enchantment.

Create X 1/1 blue Elemental creature tokens with flying.
Augmented — If you've spent {W}{U}{B}{R}{G} to cast spells this turn, creatures you control gain haste and vigilance until end of turn.

When Outside the Airlock enters, create a tapped 3/2 green Horror creature token.
Whenever a creature you control dies, each opponent loses 1 life and you gain 1 life.

When P-3 Ambusher enters, you may sacrifice a creature or discard a creature card. If you do, draw a card.

When Pantheon Breaker enters, each opponent sacrifices an enchantment.

Colossal 2—{5}{G}{U} (You may cast this for its colossal cost to have it enter with two +1/+1 counters; or pay {5}{G}{U} as a sorcery: Put two +1/+1 counters on it if it has none.)
Flying
Each creature you control with a counter on it has vigilance and “{T}: Add one mana of any color.”

Enchant creature you control
Enchanted creature has “{T}: Look at the top two cards of your library. Put one of them into your hand and the other into your graveyard.”
{6}{U}{U}, Exile Perceive Eons from the battlefield or your graveyard: Shuffle your graveyard into your library. Take an extra turn after this one. Activate only as a sorcery.