msem-instigator

When Suburban Runebrawler enters, exile target instant or sorcery card with mana value 2 or less from your graveyard.
Landfall — Once each turn, when a land you control enters, you may cast a copy of the exiled card without paying its mana cost.

Subway Shambler can't be blocked by creatures with lesser power.
At the beginning of each end step, if you're horrific, put a +1/+1 counter on Subway Shambler. (You're horrific as long as you've sacrificed a permanent or discarded a card this turn.)

Tithe (As you cast this spell, you may tap three artifacts and/or creatures you control.)
You may cast this spell as though it had flash if its tithe is paid.
Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.

Target creature can't block this turn.
Inscribe {1}{R} ({1}{R}: Exile this 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.)

As an additional cost to cast this spell, put a -1/-1 counter on a creature you control.
Search your library for up to two basic land cards, put them onto the battlefield tapped, then shuffle.

Trample, haste
Whenever Sugon, Destruction's Fist deals combat damage to a player, return it to its owner's hand unless you have Sugon deal 5 damage to you.

Flying
Suisei the Southern Star gets +1/+1 for each comet counter you have.
Whenever you cast an instant or sorcery spell with mana value greater than the number of comet counters you have, you may pay {R}. If you do, return Suisei from your graveyard to the battlefield, then you get a comet counter.

Prowess
Disgraced 2 (This enters with two -1/-1 counters. Whenever it deals combat damage to a player, remove all -1/-1 counters from it.)

When Suitor of the Glade enters, put two +1/+1 counters on target creature you control. It gains vigilance until end of turn.

At the beginning of your upkeep, Suitor of the Sea deals 1 damage to each player.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
{5}{R}: Sullivan's Courier gets +2/+2 until end of turn.

Renown 1 (When this creature deals combat damage to a player, if it isn't renowned, put a +1/+1 counter on it and it becomes renowned.)
Whenever Sullivan's Heralds or another creature you control becomes renowned, add mana equal to the number of +1/+1 counters on it in any combination of {R} and/or {G}. Until end of turn, you don't lose this mana as steps and phases end.

Enchant creature
Enchanted creature has base power and toughness 3/3.

Scry 3, then reveal the top card of your library. If it's a land card, put it onto the battlefield. Otherwise, distribute X +1/+1 counters among any number of target creatures you control, where X is that card's mana value.

Scry X, where X is the highest toughness among creatures you control, then reveal the top card of your library. If it's a creature with mana value X or less, you may put it onto the battlefield.

Reveal the top four cards of your library. Put up to two creature cards with mana value 3 or less from among them onto the battlefield and the rest into your graveyard.
Prophecy {2}{G} (Once each turn, you may exile a card with prophecy as you reveal it. When you do, you may cast it for its prophecy cost as long as it's exiled.)

{2}: Other creatures you control get +1/+0 until end of turn.
Whenever Sun-Crowned Flagship attacks, each attacking creature you control gains trample until end of turn.
Crew 7 (Tap any number of creatures you control with total power 7 or greater: This Vehicle becomes an artifact creature until end of turn.)

{W}: Target creature gains vigilance until end of turn.

You may pay {W}{U}{B}{R}{G} rather than pay this spell's mana cost.

Sundappled Scrub enters tapped unless you control another Desert.
{T}: Add {G} or {W}.

Equipped creature gets +1/+0 and gains “Whenever this creature deals damage to a player or planeswalker, you may draw two cards. If you do, discard a card.”
Equip {2}

When Sundering Arcanist enters, you may destroy target artifact or enchantment.
If you would draw a card, you may sacrifice a land and mill four cards instead. If you do, return Sundering Arcanist from your graveyard to your hand.

Whenever a land you control enters or a land card is put into your graveyard from anywhere, create a 0/1 green Plant creature token.
{3}{G}{G}: Put a +1/+1 counter on each other creature you control.

{1}, {T}: End the turn. Activate only during your turn.

As Sunflower Fields enters, you may pay 3 life. If you don't, it enters tapped.
{T}: Add {R}, {G}, or {W}.