msem-instigator

Improve {G} ({G}: Put a +1/+1 counter on this creature. This costs {1} more to activate for each +1/+1 counter on it. Improve only as a sorcery.)
Whenever an Elf you control dies, you may search your library for a land card, reveal it, put it into your hand, then shuffle.

If you've lost life this turn, you may cast this spell as though it had flash.
Return X target cards with different mana values from your graveyard to your hand. Put Studies Past on the bottom of its owner's library.

Investigate ten times. (Create ten colorless Clue artifact tokens with “{2}, Sacrifice this artifact: Draw a card.”)

Reveal the top four cards of your library. You may put one into your hand and the rest into your graveyard.
Compose (Then if you cast this from your hand, exile it and create a Saga token with “r3—You may cast a copy of this card from exile without paying its mana cost.”)

At the beginning of combat on your turn, if you control six or more lands, put a +1/+1 counter on target creature you control.

Concord — At the beginning of combat on your turn, if there are four or more card types among permanents you control, Sturdyshell Hammerclaw gets +2/+1 and gains trample until end of turn.

Flying
{B}, Sacrifice another creature: Draw a card.

({T}: Add {B}.)
As Stygian Dunes enters, you may pay 1 life. If you don't, Stygian Dunes enters tapped.

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

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.)

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.