msem-instigator

{T}: Add {C}.
{1}: Hoof Cliff Horngrove becomes a 2/2 Elemental creature until end of turn. It's still a land.
Menagerie — Whenever Hoof Cliff Horngrove becomes a creature, it gains your choice of +1/+1, flying, first strike, lifelink, trample, or haste until end of turn. This ability triggers only if there are five or more creature types among creatures you control.

Tap up to two target creatures. Scry 1. (To scry 1, look at the top card of your library. You may put that card on the bottom of your library.)

When Wistful Fox enters, reveal the top eight cards of your library. You may put a creature card from among them into your hand. Put the rest on the bottom of your library in a random order.

{T}, Sacrifice a creature: Target player discards a card and loses 1 life. Activate only as a sorcery.

When Smoldering Husk dies, it deals 2 damage to any target.
{2}{R}: Smoldering Husk gets +2/+0 until end of turn.

Defender, deathtouch
Homestead Watcher gets +2/+0 and can attack as though it didn't have defender as long as you control another creature with defender.

When Frantic Efreetspeaker enters, you may discard a card. If you do, draw a card.
{2}, Exile Frantic Efreetspeaker from your graveyard: Create a Treasure token. (It's an artifact with “{T}, Sacrifice this artifact: Add one mana of any color.”)

Search your library for a card, exile it face down, then shuffle. For as long as that card remains exiled, you may cast it. It costs {2} more to cast this way if you don't control a legendary creature as you cast that spell.

Haste
Winnow (Damage dealt to this creature also causes you to lose that much life.)

Deathtouch
Islandcycling {1}, mountaincycling {1} ({1}, Discard this card: Search your libary for an Island or Mountain card, reveal it, put it into your hand, then shuffle.)

Enchant creature or planeswalker
Enchanted permanent can't attack, block, or transform, and its activated abilities can't be activated.

Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.
Fabled {3}{R}{R} (Then if you cast this for its fabled cost, put it onto the battlefield transformed attached to that creature.)

Flash
Whenever this enchantment enters, draw a card.
Whenever you cast your first spell during each opponent's turn, draw a card.
Foretell {2}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Flying, trample
Once during each of your turns, you may cast a spell from your graveyard without paying its mana cost.
When Yhzag, Alpha and Omega is put into a graveyard from anywhere, its owner shuffles their graveyard into their library.

[+1]: Exile up to one other target nonland permanent. As long as it remains exiled, its owner may pay {1} as a sorcery to put it onto the battlefield.
[–3]: Choose 0, 1, or 2. Each player sacrifices that many creatures.
[–4]: You get an emblem with “If a nonland, nontoken permanent would enter and it wasn't cast, you may exile it instead.”

Enchant creature
Enchanted creature doesn't untap during its controller's untap step.
Untap each Horror you control during enchanted creature's controller's untap step.

Each creature you control with power 4 or greater can't be blocked by creature tokens.

Investigate, then target creature gets -1/-1 until end of turn for each Clue you control. (Create a colorless Clue artifact token with “{2}, Sacrifice this artifact: Draw a card.”)

Mark (Whenever this creature attacks, mark target creature until end of turn.)
Whenever Backalley Silencer deals combat damage to a player, destroy target marked creature.

Desiccated Trail enters tapped unless you control another Desert.
{T}: Add {W} or {B}.

Whenever Encouraging Bulwark attacks, you may put a +1/+1 counter on each creature you control that's enchanted and/or has one or more counters on it.

[+2]: Each opponent loses 2 life. Scry 2.
[–3]: Return target creature to its owner's hand. That player discards a card.
[–6]: You get an emblem with “Whenever a player discards a card, you may cast it without paying its mana cost.”

Elf creatures you control get +2/+2 and gain trample until end of turn.
Elfcycling {2}{G} ({2}{G}, Discard this card: Search your library for an Elf card, reveal it, and put it into your hand, then shuffle.)

Choose one —
• Return target nonland permanent to its owner's hand.
• Put the bottom two cards of your library into your hand.