msem-instigator

Murky Path enters tapped unless you control one or fewer other lands.
{T}: Add {U} or {B}.
Cycling {2} ({2}, Discard this card: Draw a card.)

{T}, Pay 1 life: Add {B}.
{T}, Pay 1 life, Sacrifice Murky Peat: Search your library for a Swamp card, put it onto the battlefield tapped, then shuffle.

({T}: Add {U} or {B}.)
Whenever Murmuring Falls becomes tapped, you lose 1 life unless you control two or more basic lands.

Untap all creatures that attacked this turn. After this main phase, there is an additional combat phase followed by an additional main phase. For each planeswalker you control, you may activate its loyalty abilities an additional time this turn.

At the beginning of your upkeep, germinate. Then if creatures you control have total power 10 or greater, transform Mushroom Merchant. (To germinate, put a +1/+1 counter on a creature or create a 1/1 green Saproling creature token.)

Counter target enchantment, instant, or sorcery spell. (Then exile this card. You may cast the creature later from exile.)

Put a +1/+1 counter on up to one target creature. (Then exile this card. You may play the land later from exile.)

You may have Mutalithic Golem enter as a copy of any land on the battlefield, except it's an artifact in addition to its other types.

First strike
When Mutilated Warrior enters, you may have it deal damage to each player equal to the number of Warriors you control.

Equipped creature gets +2/+2.
Concord — Whenever equipped creature attacks, if there are four or more card types among permanents you control, create a 3/3 red Shark enchantment creature token that's tapped and attacking. Exile that token at the beginning of the next end step.
Equip {1}

Whenever a card is put into a graveyard this turn, you may put it on the bottom of its owner's library.
Draw a card.

As Mysterious Cataract enters, you may pay 2 life. If you don't, Mysterious Cataract enters tapped.
{T}, Sacrifice Mysterious Cataract: Search your library for a Forest or Island card, put it onto the battlefield, then shuffle.

{X}, Exile Mysterious Coffer: Return all nonland permanents with mana value X or less to their owner's hands.

(As you complete a condition, decode it. After all are decoded, you solve the mystery and transform this.)
When Mystery of the Crashed Craft enters, create two 1/1 red Alien creature tokens with “This creature can't block.”
{MG}—You cast an instant spell.
{MG}—You cast a sorcery spell.

(As you complete a condition, decode it. After all are decoded, you solve the mystery and transform it.)
When Mystery of the Dying Herds enters, create a 0/2 white Ox creature token.
A creature you control dies.
You have 4 or more life than your starting life total.

Search your library for up to two cards with different names and reveal them. Target opponent chooses one of those cards. Put the chosen card into your graveyard and the rest into your hand. Then shuffle.

Whenever you cast a spell from exile, you may draw a card.
At the beginning of your upkeep, you may reveal the top card of your library.

Whenever a player casts a spell, that player exiles the top card of each library face down.
Each player may look at and play cards they exiled with Mystic of Many Winds.

Reverberate {2}{G} (When you cast this spell, copy it if you paid its reverberate cost. The copy becomes a permanent when it resolves.)
Mystical Echo gets +1/+1 for each other Reflection you control.
Whenever you discard a card, Reflections you control gain trample until end of turn.

{T}: Mystical Elk becomes a copy of target creature card in your graveyard. Activate only as a sorcery. (It loses this ability.)

You draw X cards and you lose X life, where X is the number of cards in your graveyard.

{R}, Sacrifice Nacatl Skirmisher: Destroy target artifact.
Stampede — Whenever Nacatl Skirmisher and a creature with greater power attack, creatures you control get +1/+0 until end of turn.

Haste
Whenever Nadei deals combat damage to a player, that player sacrifices a land. You may put a land card from a graveyard onto the battlefield under your control.

Flying
Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
At the beginning of each end step, scry X, you gain X life, and Nakia, Infinity Seer deals X damage to up to one target creature or planeswalker, where X is the number of noncreature spells you've cast this turn.

{2}{U}, Sacrifice Nameless Drifter: Draw a card for each creature that left the battlefield this turn.