msem-instigator

{3}, {T}: Scry 3.
{5}, {T}: Fateseal 3.
{7}, {T}: Draw two cards.

{T}: Add {C}.
{7}, {T}: Create a 2/2 colorless Spirit creature token.

When Seishin Rageshaper enters, create a 2/2 colorless Spirit creature token.
Colorless creatures you control have haste.

When Seishin Smokeshaper enters, create a 2/2 colorless Spirit creature token.
Whenever you cast a noncreature spell, colorless creatures you control get +1/+1 until end of turn.

Equipped creature gets +1/+0 for each colorless creature you control.
Equip {1}

Concord — This spell costs {4} less to cast if there are four or more card types among permanents you control.
Vigilance, trample, lifelink, haste

Destroy target land. Add {R}{R}.

Seismic Strike deals damage to target creature equal to the number of Mountains you control.

Another target player reveals their hand. You may choose an instant or sorcery card from it and cast it without paying its mana cost.
Fuse (You may cast one or both halves of this card from your hand.)

Equipped creatures you control get +1/+1.
You may activate equip abilities any time you could cast an instant.
Equip {2}

As an additional cost to cast this spell, sacrifice a creature.
Search your library for a creature card that shares a creature type with the sacrificed creature with mana value less than or equal to X plus the sacrificed creature's mana value, put it onto the battlefield, then shuffle.

{3}: Sellsword Contraption becomes the creature type of your choice until end of turn.

Instant and sorcery spells you cast cost {1} less to cast.
Rapport — Whenever Selma Lappowen and at least one other creature you control become tapped, exile the top card of your library. Until end of turn, you may play that card.

Until end of turn, target creature you control gains double strike and trample. Sacrifice it at the beginning of the next end step.
Draw a card.

You may put cards with Adventures that permanents you control explore into your hand as though they were lands. (You won't get the counter if you do.)
At the beginning of each end step, if you cast an Adventure spell or a permanent you controlled explored this turn, create a 1/1 green Scout creature token.

When Sentient Contraption enters, create a 1/1 colorless Thopter artifact creature token with flying.

Reach, ward {3}

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 has vigilance and reach.
Equip {3} ({3}: Attach to target creature you control. Equip only as a sorcery.)

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

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.

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.

Mill four cards, then return a creature or enchantment card from your graveyard to you hand. You gain 3 life.