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.

Sacrifice another colorless creature: Put a +1/+1 counter on target creature.

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

Multipurpose Mannequin gets +1/+1 for each permanent attached to it.

{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 the battlefield, you may pay {1}. If you don't, Mushroom Lagoon enters the battlefield 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.

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

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}

As Mysterious Cataract enters the battlefield, you may pay 2 life. If you don't, Mysterious Cataract enters the battlefield 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.

Equipped creature gets +1/+1.
Equip {1}

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

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

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

Deathtouch
When Necrodromos enters the battlefield, put a +1/+1 counter on target creature.

Equipped creature has all activated abilities of all creature cards in your graveyard.
Equip {3}

Equipped creature gets +0/+2.
Whenever equipped creature blocks, you may pay {B}. If you do, target player loses 1 life.
Equip {2}

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

Nestled Delta enters the battlefield 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.”