msem-instigator

Soldiercycling {1}{W}, Wizardcycling {1}{U}, Zombiecycling {1}{B}, Warriorcycling {1}{R}, Elfcycling {1}{G} ({1}{G}, Discard this card: Search your library for an Elf card, reveal it, and put it into your hand, then shuffle.)
Sentinel of Latter Days is every creature type as long as it's in your library.

Sentinel of the Highlands has hexproof 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.)

Equipped creature gets +2/+0. As long as it's a Knight, it has first strike.
Equip {1}{W}

Flying, vigilance
Whenever Sepulchral Guide attacks, prevent all combat damage that would be dealt to another target creature you control this turn. If that creature has two or more counters on it, untap it.

Deathtouch, menace
As long as you control another Knight creature, Ser Joffrey, Plague of Nines and other Knight creatures you control have first strike.

Trample
Ser Malcomn's power and toughness are each equal to the number of nonbasic lands your opponents control.

Sera of Coppercove attacks each combat if able.
Whenever Sera of Coppercove attacks, it fights target creature you don't control.
{1}{R}{G}: Sera of Coppercove gets +3/+3 until end of turn.

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.

Flying, vigilance, lifelink
Persist (When this creature dies, if it had no -1/-1 counters on it, return it to the battlefield under its owner's control with a -1/-1 counter on it.)

Flying
Whenever you cycle Seraph of the Stage or it attacks, audition for white. (Create a 1/1 Construct Actor creature token, a Scout Role giving 2/3 and vigilance, or a Cleric Role giving 2/2 and lifelink. Roles replace older ones.)
Basic landcycling {1}{W} ({1}{W}, Discard this card: Search your library for a basic land card, reveal it, and put it into your hand, then shuffle.)

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.

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}

[+1]: You may sacrifice a permanent. If you do, each opponent sacrifices a permanent that shares a type with it.
[–2]: Put target creature card in a graveyard onto the battlefield under your control.
[–8]: You control target player during their next turn. During that turn, that player may cast spells by paying life equal to their mana value rather than pay their mana cost. After that turn, that player takes an extra turn.

For each permanent type, you may put a permanent card of that type from your hand onto the battlefield. Exile Set the Stage.

Menace
When Setar Ritualist enters or whenever you cast a spell, if {U}{R} was spent to cast it, Setar Ritualist deals 3 damage to target permanent, then tap that permanent. Put a +1/+1 counter on Setar Ritualist.

Equipped creature gets +2/+2 and has ward {2} and “Whenever this creature attacks, draw a card, then you may put a land card from your hand onto the battlefield.”
Equip {2}

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

Settle the Dust deals 4 damage to each tapped creature.

When Settlement Establishment enters, draw a card, then choose a card name.
Whenever an opponent casts a spell with the chosen name, counter that spell, then that opponent creates a Plains token.

Once each turn, when another creature you control enters, you may search your library for a card with the same name as that creature, reveal it, put it into your hand, then shuffle.

At the beginning of your upkeep, you may pay {B}. If you do, return a Wizard card from your graveyard to your hand.

For each player, exile target creature or planeswalker they control.

Whenever an artifact is put into your graveyard from the battlefield, you may draw a card. If you do, discard a card.
{T}, Exile three noncreature cards from your graveyard: Create a 1/1 colorless Construct artifact creature token.

Exile two target cards from your graveyard. If they share a card type, draw a card. (Then exile this card. You may cast the creature later from exile.)

As long as Sewer Pack is on the battlefield, you may cast spells named Sewer Pack from your graveyard.
Sewer Pack gets +1/+1 for each other creature on the battlefield named Sewer Pack.