msem-instigator

When Smokeweaver Initiate dies, draw a card.

Whenever you discard an instant or sorcery card, you may cast it from your graveyard. (You still pay its costs.)
Spells you cast from anywhere other than your hand cost {1} less to cast.

When Sofia's Swashbucklers enters, you may return target card with foretell from your graveyard to your hand.

First strike

Menace
Whenever a nontoken Warrior you control dies, create a token that's a copy of it, except it's 1/1.

Whenever Soli Arbalist or a nontoken Angel or Nephilim you control enters, amass Soldiers 2. If it was an Angel, amass Soldiers 4 instead. (To amass Soldiers {2}, put two +1/+1 counters on an Army you control. It's also a Soldier. If you don't control one, create a 0/0 black Soldier Army creature token first.)

When Soli Chronicler enters, judge another target creature you control. (Honor it by putting a +1/+1 counter on it or condemn it by sacrificing it to draw a card.)

At the beginning of each player's upkeep, that player may pay {2} or 2 life. If they don't, they return a permanent they control to its owner's hand.

Whenever another creature you control enters, target opponent loses 1 life and you gain 1 life.
Sacrifice Somber River Bearer: Creatures you control gain indestructible until end of turn.

Somberwald Rider can't be blocked by creatures with power 2 or less.
{2}{G}: Transform Somberwald Rider. Activate only if it's attacking.

Improve {1} ({1}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
At the beginning of your upkeep, exile up to one target nonland permanent you own. Return that card to your hand. If Soul Reader has two or more counters on it, you may instead return that card to the battlefield under your control.

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
When Soul Trapper enters, tap target creature an opponent controls. That creature doesn't untap during its controller's untap step for as long as you control Soul Trapper.

Other Spirits you control get +1/+1.
As long as a Spirit you control has flying, Soulcleaver has flying. The same is true for first strike, double strike, deathtouch, haste, hexproof, indestructible, lifelink, menace, reach, trample, and vigilance.

At the beginning of each end step, if you gained life this turn, put a +1/+1 counter on a creature you control.

Flash
Other Rogues you control get +1/+1.
Rogue spells you cast have flash.

Soulsmoke Adept gets +1/+0 and has lifelink as long as it's embattled. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

First strike
When Soulstone Commander enters, return target Soldier creature card from your graveyard to the battlefield. That creature is a Spirit in addition to its other types.

Bulwark — Whenever Soulstone Servant attacks, if you control a creature with toughness 4 or greater, Soulstone Servant gets +2/+2 and gains flying until end of turn.

Whenever a land you control enters, you gain 1 life.
{3}{G}, Sacrifice Sower of Spring: Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Flying
When Spawn of Keranos enters, you may draw a card. If you do, discard a card unless you control another creature with flying.

Each creature you control that has been dealt damage this turn by a source you controlled has indestructible.

Haste
When Speaker of the Iris enters, abound. (To abound, you may cast a spell that costs less than this from your hand without paying its mana cost.)
Other creatures you control have haste.

When Specialist Saboteur enters, choose one —
• Put a +1/+1 counter on Specialist
Saboteur.
• Destroy target enchantment.

Whenever you cast a noncreature spell, create a 1/1 colorless Servo artifact creature token.
{1}{U}, {T}, Exile three noncreature cards from your graveyard: Draw a card.

When Specimen Collector enters, you may salvage a creature card. (Exile one from your graveyard until this creature leaves the battlefield. Whenever this creature deals combat damage to a player, put a card it salvaged into your hand.)