msem-instigator

(Transform this if it's not attached to a creature. Pay {3}{R}{R} as a sorcery to unattach it.)
Enchant creature you control
Mount of the Order's rider gets +5/+4.
{2}{R}: Target creature can't block Mount of the Order's rider this turn.

Menace
At the beginning of your end step, Mountain Tyrant deals 1 damage to each creature you don't control.

({T}: Add {U} or {B}.)
Muggy Mire enters tapped unless you control two or more basic lands.

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.

({T}: Add {G} or {U}.)
As Mushroom Lagoon enters, you may pay {1}. If you don't, Mushroom Lagoon enters tapped.

{T}: Add {C}.
Whenever Mustering Grounds becomes tapped, if it's enchanted, you may pay {2}. If you do, create a 1/1 white Soldier creature token with vigilance.

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.

{T}: Add {C}.
{3}, {T}, Sacrifice Mystical Tomb: Return target artifact, enchantment, or legendary card from your graveyard to your hand.

Naxila, the Blessed City enters tapped.
When Naxila, the Blessed City enters, you gain 2 life and draw two cards.
{T}: Add {C}{C}.

Neblus' Legacy enters tapped.
When Neblus' Legacy enters, you may mill two cards.
{T}: Add {G} or {U}.

As Nebula of Empty Gold enters, choose two or three colors. You lose life equal to the number of colors chosen this way.
{T}: Add one mana of any of the chosen colors.

{T}: Add {C}.
Wanderlust — {6}, {T}: Draw two cards. Activate only if you control four or more differently named lands.

Nestled Delta enters tapped unless you control another Desert.
{T}: Add {G} or {U}.

{T}: Add {C}.
Satrapies you control have “{1}, {T}: Add one mana of any color.”

As New Divide enters, you may pay 2 life. If you don't, it enters tapped.
{T}, Sacrifice New Divide: Search your library for a basic land card, put it onto the battlefield, then shuffle.

Whenever a creature deals combat damage to you, that creature's controller gains control of Nightmare Alley.
{T}: Add {C}.
{1}, {T}: Target attacking creature gets +1/+0 until end of turn and can't be blocked this turn.

Nightshaper's Domain enters tapped.
{T}: Add {B}.

Flying
At the beginning of your upkeep, mill seven cards, then you may cast an instant or sorcery card from your graveyard. If that spell would be put into your graveyard, exile it instead.
If you would draw a card while your library has no cards in it, you win the game instead.

Nightwatch Rallier enters with X +1/+1 counters on it.
Other artifact creatures you control get +1/+1 for each +1/+1 counter on Nightwatch Rallier.

Nilchain Altar enters tapped.
{T}: Add {W} or {B}.
{W}{B}, {T}, Sacrifice Nilchain Altar: Conjure a card named Data-Point into your hand. (It's a sorcery that costs {2} with “Draw a card.”)

Indestructible
When this creature transforms into Ninhasir, God of Creation, discard all the cards in your hand, then draw that many cards plus one.
Whenever you cast an instant or sorcery spell, copy it. You may choose new targets for the copy.

{T}: Add {C}.
Satrapies you control have “{U}, {T}: Each opponent mills a card.