msem-instigator

Deathtouch
When The Terror of Shady Cove enters, target opponent sacrifices an artifact. If they can't, create a 3/3 green Slug creature token with deathtouch. Then repeat this process for an enchantment and a nonbasic land.

When The Third Breach enters, discard your hand, then draw seven cards.
Creatures you control get +3/+3, have haste, and are Horrors in addition to their other types.
At the beginning of each end step, sacrifice each creature you control.

For each creature, its owner puts it on the top or bottom of their library.

{T}: Add {C}.
{1}, {T}: Draw a card, then discard a card. Activate only if seven or more cards are in your graveyard.

Defender
Your maximum hand size is thirteen.
{T}: If you have fewer than thirteen cards in hand, draw cards equal to the difference. Activate only as a sorcery.

The Unshakable Kian enters with three wish counters on him.
Remove a wish counter from Kian: Choose one. Activate only as a sorcery and only once each turn.
• Kian gains hexproof and trample until your next turn.
• Tap up to three target nonland permanents and put a stun counter on each of them.
• If you have fewer than four cards in hand, draw cards equal to the difference.

Whenever you sacrifice a Clue, you lose life equal to the number of Clues you control, then investigate twice. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

[0]: Creatures you control gain haste until end of turn. Whenever a creature attacks this turn, put a loyalty counter on The Warrior Within.
[–1]: Exile the bottom two cards of your library. You may play one of them this turn.
[–6]: Untap each creature that attacked this turn. After this main phase, there is an additional combat phase.

Creatures you control get +2/+0 until end of turn.
Metamorph {1}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up and cast it at any time for its metamorph cost.)

{T}: Add {C}.
{1}, {T}, Sacrifice The Whisperwoods: Add two mana in any combination of colors.
At the beginning of each end step, if a player lost life this turn, return The Whisperwoods from your graveyard to your hand.

Whenever The Wicker Lord or another Scarecrow you control enters, create a 1/1 black Bird creature token with flying for each Scarecrow you control.
{4}, Sacrifice a Scarecrow: Return target artifact card from your graveyard to the battlefield.

Whenever The Winged Steed attacks, create a 4/4 red Dragon creature token with flying that's tapped and attacking. Exile that token at end of combat.
Crew 2 (Tap any number of creatures you control with total power 2 or greater: This Vehicle becomes an artifact creature until end of turn.)

[+2]: The Witch Queens deal 2 damage to each of up to two targets.
[–3]: Gain control of target land and untap it.
[–9]: Each player discards their hand, then draws up to seven cards. The Witch Queens deal damage to each opponent equal to twice the number of cards that player has drawn this turn.

Search your library for two basic land cards that don't share a land type and put them onto the battlefield tapped.
{W}{U}{B}{R}{G}, Exile The World Follows After from your graveyard: Create a 4/4 Elemental creature token that's all colors. It can't block this turn.

Extort (Whenever you cast a spell, you may pay {W/B}. If you do, each opponent loses 1 life and you gain that much life.)

Equipped creature gets +1/+0 and can't be blocked.
Equip Actor creature {1}
Equip {3}

Target opponent discards two cards. You create a 0/1 black Cultist creature token with “{1}{B}{B}, Sacrifice three Cultists: Create a 5/5 black Demon creature token.”

Prowess
Whenever you cast a noncreature spell, audition for blue or for red. (Create a 1/1 Construct Actor creature token, a Wizard Role giving 2/2 and prowess, a Warlock Role giving 2/1 and flying, or a Warrior Role giving 3/2 and trample. Roles replace older ones.)

(As this Discovery enters and after your draw step, add a progress counter. Stop after you've discovered.)
I, II — Look at the top five cards of your library. Put up to one creature card with mana value 2 or less from among them onto the battlefield. Put the rest on the bottom of your library in a random order.
Discovery — At the beginning of combat on your turn, tap target creature an opponent controls.

As Theodore Harper, Head Librarian enters, choose Fact or Fiction.
• Fact — Permanent spells you cast cost {1} less to cast. This effect can't reduce the amount of mana a spell costs to cast to less than one mana.
• Fiction — When Theodore Harper enters, return a permanent card from your graveyard to your hand.

{T}: Draw a card. Activate only if Theoretical Scholar is embattled. (A creature is embattled if it has a counter on it or a permanent you control attached to it.)

Flying, haste
Thermal Surger can't block.
When Thermal Surger enters, you may sacrifice a land or exile a land card from your graveyard. If you do, put a +1/+1 counter on Thermal Surger.

Enspirit (As you cast this spell, you may exile a nonenchantment creature you control until this leaves the battlefield or fails to resolve. Reduce this spell's cost by the exiled card's mana value.)
At the beginning of your upkeep, create a token that's a copy of the enspirited card. It gains haste until end of turn. Exile it at the beginning of the next end step.

If a source you control would deal damage this turn, it deals double that damage instead.
Coalesce {7}{R}{R} (You may cast this from your graveyard for {7}{R}{R}. If you do, it enters as a Horror creature after it resolves. Exile it if it would leave the battlefield or not resolve.)
Haste

{2}{R}: Thespian Soldier gains first strike until end of turn.