msem-instigator

Draw two cards, then you may discard a card. If you do, target opponent reveals their hand. You choose a noncreature, nonland card from it. That player discards that card.

Siphon (Each -1/-1 counter you put on your creatures up to their remaining toughness while casting this pays for {1}.)
Draw three cards.

Solar Hatching deals 4 damage to each creature.
Coalesce {6}{R}{R} (You may cast this from your graveyard for {6}{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.)
When Solar Hatching enters, each player chooses up to two lands they control and sacrifices the rest.

{T}: Add {C}.
{T}, Exile two cards from your graveyard: Add {B} or {R}.

Legacy (You may play this side of this card only from your graveyard. Exile it if it would be put into a graveyard or not resolve.)
For each of up to two target creatures you control, put a +1/+1 counter on it, then you may have it deal damage equal to its power to any target.

Double strike, menace, trample
At the beginning of your end step, sacrifice Juddering Mishap unless you've cast a spell with no creature types this turn. (Noncreature spells have no creature types.)

Flying
Whenever an opponent draws a card except for the first time each turn, create a 1/1 blue Elemental creature token with flying.
Foresight — Whenever you draw your second card each turn, creatures you control get +1/+1 until end of turn.

Create X 1/1 black Goblin creature tokens. Gain control of target permanent with mana value X or less until end of turn. Untap it. It gains haste until end of turn.

{T}, Sacrifice Palace of Reflections: Choose a land you control. Search your library for a land card with the same name as the chosen land, put it onto the battlefield tapped, then shuffle.

Search your library for a basic land card and put that card onto the battlefield tapped, then shuffle.
Create a Vial token. (It's an artifact with “{1}, Sacrifice this and another permanent: Draw a card. Activate only during your turn.”)

When Silvercrest Historian enters, scry 1, then investigate. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Target player discards a card.
Amass Soldiers 1. (Put a +1/+1 counter on an Army you control. It's also a Soldier. If you don't control one, create an 0/0 black Soldier Army creature token first.)

Search your library for a land card and put that card onto the battlefield tapped with a venom counter on it. It gains “Whenever this land is tapped for mana, you lose 1 life.” Then shuffle.

When Mausoleum Rite enters, each player mills four cards.
{2}{B}, Exile a creature card from your graveyard: Create an Idol token. (It's an artifact with “{1}, Sacrifice this artifact: Put a +1/+1 counter on target creature. Activate only as a sorcery.”)

Exile target creature if its controller controls more lands than you.
Cycling {2} ({2}, Discard this card: Draw a card.)

When Keeper of the Ancient Ways enters, destroy up to three target noncreature, nonland artifacts and/or enchantments with total mana value 3 or less.

As Imperial Barracks enters, you may reveal a Mountain or Plains card from your hand. If you don't, Imperial Barracks enters tapped.
{T}: Add {R} or {W}.

Vanishing 3 (This permanent enters with three time counters on it. At the beginning of your upkeep, remove a time counter from it. When the last is removed, sacrifice it.)
When the last time counter is removed from Rising Riots, destroy target land.

If a creature card would be put into an opponent's graveyard from anywhere, instead exile it, then copy it. You may cast the copy. (You still pay its costs, including color. Copies of permanents enter as tokens.)

This spell costs {2} less to cast if your starting deck contained at least forty cards more than the minimum deck size.
When Unrivaled Fireweaver enters, you may exile a red instant or sorcery card you own from outside the game. Until the end of your next turn, you may play that card.

Gestalt (When this or another creature enters under your control, you may merge it with the one in play, keeping counters and attachments. They become the permanent on top plus all abilities from under it.)
This creature can't be sacrificed.

Kinsang Shrine enters tapped.
{T}: Add {B} or {G}.
{B/G}, {T}, Sacrifice Kinsang Shrine: Put a +1/+1 counter on target creature you control. Activate only as a sorcery.

Flying, lifelink
{2}{W}{W}, Exile Archon of Sunrise from your graveyard: Create a token that's a copy of it, except it's an Aura enchantment with enchant creature and “Enchanted creature gets +4/+4 and has flying and lifelink.” Activate only as a sorcery.

When Backstage Tinkers enters, you may return an artifact card from your graveyard to your hand.

This spell can't be countered.
Hexproof (This creature can't be the target of spells or abilities your opponents control.)
Haste (This creature can attack and {T} as soon as it comes under your control.)