msem-instigator

{T}: Add {C}. Spend this mana only to cast a creature spell with a creature type no creature you control has.

(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 the battlefield, create a 1/1 red Alien creature token.
{MAG}—You cast an instant spell.
{MAG}—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 the battlefield, create a 0/2 white Ox creature token.
I — A creature you control dies.
II — You have 4 or more life than your starting life total.

When Mystic Mackerel enters the battlefield, you may have target player mill two cards.
{3}{U}, Sacrifice Mystic Mackerel: Return target enchantment, instant, or sorcery card from your graveyard to your hand.

{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.

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

Return target creature you control to its owner's hand. You gain life equal to its power.

Destroy target artifact or enchantment. Its controller gains 4 life.

Put a +1/+1 counter on target creature.
Flashback {1}{G} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Defender (This creature can't attack.)
When Naturebound Druid enters the battlefield, you may search your library for a basic land card, reveal it, then shuffle and put that card on top.

Exile target permanent you control, then return that card to the battlefield under your control.

Search your library for a basic land card, reveal it, put it into your hand, then shuffle.
Add one mana of any color.

Deathtouch
When Nel Toth Shaman enters the battlefield, mill two cards.

Whenever Neo-Soul Attendant or another enchantment enters the battlefield under your control, you gain 1 life.

Whenever Netsight Trickster deals combat damage to an opponent, create a Function token with “Draw a card. Then discard a card unless you pay {2}.” (It's an enchantment. As you cast an instant or sorcery spell, sacrifice any number of Functions to add their effects to that spell.)

Counter target instant or sorcery spell unless its controller pays {3}.

Harmony — You gain 2 life.
When New Alores Fiddler enters the battlefield, harmonize. (Trigger up to one harmony of one permanent you control.)

Create a 1/1 white and black Badger Cleric creature token with lifelink. (Then exile this card. You may cast the creature later from exile.)

Menace
Ni'Ama's Emissary gets +1/+1 as long as you control a red or white permanent.

Nimblefoot can't be blocked.

Flying
{3}{U}, Sacrifice Nimbus Fae: Put target creature on top of its owner's library.

Flying
Sacrifice Nimbus Glider: Creatures you control gain flying until end of turn.

Nip at the Heel deals 1 damage to any target. Create a 1/1 red Hound creature token.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
At the beginning of your end step, if Nizev Enforcer's power is 4 or greater, create a token that's a copy of it.

Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.)
When Northwind Master enters the battlefield, you may have another target creature you control gain prowess until end of turn.