msem-instigator

{T}: Add {C}.
{T}, Reappropriate: Add {U} or {B}. (Exile exactly two cards from your hand and/or graveyard.)

When Serafina's Gift enters, if you cast it, target opponent gains control of it.
At the beginning of your upkeep, draw three cards, then discard two cards.

Equipped creature gets +2/+0 and can't block.
Equip {1}

Serene Chapel enters tapped unless you control a basic Plains.
{T}: Add {W}.
{1}{W}{W}: Until end of turn, Serene Chapel becomes a 2/1 white Spirit Cleric creature with flying and “Whenever this creature attacks, you may exile target card from a graveyard.” It's still a land.

Prevent all damage target spell or permanent would deal this turn. You gain life equal to the damage prevented this way.

When Serene Initiate enters, rouse 1. (Put a +1/+1 counter on a permanent you control. If it isn't a creature, tap it and it becomes a 0/0 creature in addition to its other types.)
{3}{G}{G}: Creatures you control get +2/+2 and gain trample until end of turn.

{T}: Add {G} or {U}. You lose 1 life unless you have less life than an opponent.

{T}, Sacrifice Serene Trail: Search your library for a Forest or Plains card and put it onto the battlefield tapped, then shuffle.

Equipped creature gets +1/+1 and has deathtouch.
{1}: Serpent Staff becomes a 1/1 green Snake creature with deathtouch and loses all other abilities until end of turn.
Equip {3}

Serpentine Woods enters tapped.
{T}: Add {B} or {G}.
{2}{B}{G}, {T}, Sacrifice Serpentine Woods: Draw a card.

Enchant creature
Enchanted creature can't attack.
Civilized — Enchanted creature can't block and its activated abilities can't be activated if you control an artifact, a creature, and an enchantment.

Enchant player
At the beginning of enchanted player's upkeep, that player creates a 1/1 white Soldier creature token.

{T}: Add {C}.
{5}{R}{G}, {T}: Transform Settled Satrapy.

{2}: Settlement Guardian gets +1/+1 until end of turn for each color of mana spent to activate this ability.

Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

Destroy target token.

Vigilance
Sha'Iv's Emissary gets +1/+1 as long as you control a blue or red permanent.

At the beginning of your upkeep, you lose 1 life.

Shadow Courier can't be blocked.

Your opponents play with their hands revealed.

When Shadow of Izumito dies, choose one —
• Destroy target creature that was dealt damage this turn.
• You may put a progress counter on a Project you control.

Shadowband Consul enters tapped.
{B}, Pay 2 life: Return Shadowband Consul from your graveyard to the battlefield. Activate only if an opponent lost life this turn.

Shadowcleft Hideout enters tapped.
{T}: Add {B}.
{T}, Pay 2 life, Sacrifice Shadowcleft Hideout: Draw a card.

({T}: Add {B}.)
Shadowed Slums enters tapped.
{B}, {T}, Reveal a black card from your hand: Target player loses 1 life.

Sacrifice Shadowfeeder: Target player loses 1 life and you gain 1 life.