msem-instigator

When Stygian Leviathan enters, target opponent loses life equal to the number of Curses attached to them and you gain that much life.

This spell costs {1} less to cast for each Horror you control.
Exile up to one target non-Horror creature.
Coalesce {7}{W} (You may cast this from your graveyard for {7}{W}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Gain control of target noncreature permanent.
Coalesce {8}{U}{U} (You may cast this from your graveyard for {8}{U}{U}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)

Once each turn, when you discard a card, you may draw a card.
{1}, Discard a card: Substack Smuggler can't be blocked until end of turn.

Breach (Whenever this deals combat damage to a player, you may have it become an Aura Curse until your next turn. Attach it to that player.)
At the beginning of your end step, Substack Sniper deals 1 damage to you and to each cursed opponent.

Flying
Whenever a creature dealt damage by Subturgian Legionnaire this turn dies, create a 1/1 black Vampire creature token with lifelink.

When Suburban Farmer enters, you may search your library for a basic Plains card, reveal it, put it into your hand, then shuffle.
When Suburban Farmer dies, you gain 3 life.

Glitch {3}{W} (Remove one [restriction] for each time you pay the glitch cost.)
Exile target nonland permanent. [Return it to the battlefield under its owner's control at the beginning of the next end step.]

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.

Return target creature to its owner's hand. If it's tapped, you may put it into its owner's library second from the top instead.

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.)

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

When Sullen Bonecrusher enters, it deals damage to any target equal to the number of Warriors you control and you gain that much life.

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.

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.

Pay 2 life, Sacrifice a Clue: Draw a card.

Counter target creature spell. Create a 2/2 blue Illusion creature token.

As an additional cost to cast this spell, discard a card.
Draw two cards unless any opponent discards two cards.

Vigilance
Sun's Own has indestructible as long as it's your turn.

Sun-Dappled Paragon enters with a +1/+1 counter on it for each other creature you control.
Whenever another creature you control enters, put a +1/+1 counter on Sun-Dappled Paragon.

Vanguard — Whenever a creature you control attacks alone, you may cast a spell with mana value 3 or less from your hand without paying its mana cost.

Whenever another creature you control enters, Sunblessed Orator deals 1 damage to each opponent and you gain 1 life.

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

Spirited (When this creature enters, you may activate one of its activated abilities without paying its cost.)
{3}{R}{W}: Creatures you control gain flying and haste until end of turn.

Flying
When Sunchaser Mantas enters, choose a color. Look at the top four cards of your library. You may reveal a card of the chosen color from among them and put it into your hand. Put the rest on the bottom of your library in a random order.