msem-instigator

Whenever an opponent attacks you and/or one or more planeswalkers you control, you may draw a card.

Trample
{2}{R}: Santriza Arsonist gets +3/+0 until end of turn.

Menace
When Santriza Gang-Boss enters, it deals X damage to any target, where X is the number of Pirates and/or Rogues you control.

Flying
Improve—{1}{B/R}, Sacrifice a creature. ({1}{B/R}, Sacrifice a creature: 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.)
Whenever another creature you control dies, each opponent loses 1 life and you gain 1 life. If that creature was sacrificed, instead each opponent loses 2 life and you gain 2 life.

Trample
Savage Mammoth gets +1/+1 for each land you control.
Ride {4}{G} ({4}{G}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Whenever Scarhide, Arsenal Crafter attacks, create a token that's a copy of an Equipment attached to Scarhide and attach the token to Scarhide. When you can't, arm it. (Create a colorless Equipment artifact token with “Equipped creature gets +1/+0” and equip {2}, then attach it to that creature.)

Whenever Scavenger of the Old Bay deals combat damage to a player, draw a card.
Ride {1}{U} ({1}{U}: Transform this and attach it to target creature you control without a Steed. Ride only as a sorcery.)

Add three mana of any one color.

Scion of Belmord has lifelink as long as it's embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

When Scion of Sarrithaz enters, create a 2/2 black Zombie creature token.
{2}{B}, Sacrifice a creature: Draw a card.

Vigilance
Other Knights and Soldiers you control get +1/+1.
{2}{B}, {T}, Sacrifice a Knight or Soldier: Destroy target creature or planeswalker. Activate only as a sorcery.

{3}{G}: Seasoned Farmer gets +2/+2 until end of turn.

At the beginning of your upkeep, you lose 1 life and create a 1/1 white Soldier creature token with melee. (Whenever that creature attacks, it gets +1/+1 until end of turn for each opponent you attacked this combat.)

As Secluded Courtyard enters, choose a creature type.
{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type or activate an ability of a creature source of the chosen type.

Shuffle up to five target cards from your graveyard into your library. Reveal the top five cards of your library. An opponent separates those cards into two piles. Put one pile into your hand and the other into your graveyard.

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
{2}{U}: Return Sequester to its owner's hand.

When Sewer Dweller enters or dies, create a 1/1 black Rat creature token with “This creature can't block.”

Prowess
Each instant and sorcery card with mana value 3 or less in your hand has inscribe. The inscribe cost is equal to its mana cost increased by {1}{U/R}. (Pay that card's mana cost increased by {1}{U/R}: Exile that card from your hand inscribed on a creature you control. Whenever that creature attacks, its controller may cast a copy of the inscribed card without paying its mana cost. Inscribe only as a sorcery.)

Menace, lifelink
Whenever a creature enters under an opponent's control, you may have that player lose 1 life.

Destroy target artifact.

Trample
Improve {1}{R} ({1}{R}: 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.)
Embattled creatures you control get +2/+0. (A creature is embattled if it has a counter on it or has a permanent you control attached to it.)

Equipped creature gets +1/+1.
Whenever equipped creature becomes the target of a spell or ability an opponent controls, you may return Shawl of Warding to its owner's hand. If you do, counter that spell or ability.
Equip {2}

Shepherd of the People can't be blocked by creatures with power 2 or less.
Whenever another Citizen or Peasant you control enters, Shepherd of the People gets +1/+1 until end of turn.

Equipped creature has haste.
At the beginning of combat on your turn, create a token that's a copy of equipped creature, except the token isn't legendary if equipped creature is legendary. That token gains haste. Exile it at the beginning of the next end step.
Equip {2}

Equipped creature gets +1/+1.
Equip {1}