msem-instigator

{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 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, 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.

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

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.

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

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

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

{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.

When Nidohagane Warfans enters, if it's not a token, create a token that's a copy of it.
Equipped creature gets +1/+0.
Equip {1}

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.

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.

{T}: Add {C}.
{3}, {T}, Sacrifice No-Man's Land: Draw a card.

Activated abilities of other permanents cost an additional “Sacrifice a permanent” to activate unless they're mana abilities.
{2}, {T}, Sacrifice Nullifier of Planar Energy: Remove all counters from target nonland permanent.

Equipped creature has “{T}: This creature deals 1 damage to any target.”
Equip {3}

Observation Field enters with three charge counters on it.
{2}, {T}, Remove a charge counter from Observation Field: Draw a card and gain 2 life.
{T}, Sacrifice Observation Field: Shuffle any number of target cards from your graveyard into your library.

This spell costs {1} less to cast for each artifact and/or enchantment you control.
Trample
{1}, Sacrifice another cryptic permanent you control or exile a cryptic card from your graveyard: Put a +1/+1 counter on Observer of Aeons. (Artifacts, enchantments, and modal spells are cryptic.)

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

{2}, {T}, Sacrifice Old Map: Search your library for a basic land card, put it onto the battlefield, then shuffle.