At the beginning of combat on your turn, you may have target Advisor you control get +2/-1 until end of turn.

Mass of Remains's power is equal to the total number of permanent cards you own in your graveyard and in exile.
Spellcharge 3

Matter Harvester has protection from mana values less than the number of artifacts you control.
Whenever a nonland permanent you don't control leaves the battlefield, create a 1/1 colorless Cyborg artifact creature token.

Trample
Mercurial Wright gets +1/+0 for each other artifact you control.
{2}: Target permanent becomes an artifact in addition to its other types until end of turn.

When Meteorite enters, it deals 2 damage to any target.
{T}: Add one mana of any color.

Miasmic Cove enters tapped.
{T}: Add {B} or {G}.
{4}{B/G}: Miasmic Cove becomes a 2/3 black and green Snake creature with deathtouch until end of turn. It's still a land. This ability costs {X} less to activate, where X is your devotion to black and green. Activate only once each turn.

{T}: Add {C}.
{T}: Surveil 1. Return Mirage Island to its owner's hand.

Mirrormeld Spire has all abilities of land cards integrated onto permanents you control.
{T}: Add {C}.
{C}, {T}: Integrate the top card of target player's library.

Moresso, Infuser of Light is all colors.
Hexproof from monocolored
Whenever you cast a spell with four or more mana symbols in its mana cost, add four mana of different colors. This ability triggers only once each turn.

Nascent Lightvein enters tapped.
As Nascent Lightvein enters, choose a color. Then if you control three permanents that could each produce a different color of mana, untap it.
{T}: Add one mana of the chosen color.

Nebulous Ring enters tapped.
{T}: Add {C} or {W}.
{1}, Discard Nebulous Ring: Scry 2.

Neglected Slums enters tapped.
{T}: Add {R} or {G}.
{4}: Make a pledge. Activate only as a sorcery.

Neo Stehlia enters tapped unless you control a basic non-Plains land.
{T}: Add {W}.
{2}{W}, {T}: Choose a creature type. Creatures you control of the chosen type get +1/+0 until end of turn.

When Neon Colossus dies, draw a card.

Trample, ward {4}
Equipped creature gets +4/+4 and has trample and ward {4}.
Equip {4}
Spellcharge 8

Nessian Woods enters tapped.
{T}: Add {R} or {G}.
{6}{R/G}: Nessian Woods becomes a 5/4 red and green Dryad creature with trample until end of turn. It's still a land. This ability costs {X} less to activate, where X is your devotion to red and green. Activate only once each turn.

Nimbus of Thought enters tapped.
{T}: Add {U} or {R}.
{4}{U/R}: Until end of turn, Nimbus of Thought becomes a 3/3 blue and red Elemental creature with “Whenever this creature becomes tapped, you may discard a card. If you do, draw a card.” It's still a land. This ability costs {X} less to activate, where X is your devotion to blue and red. Activate only once each turn.

At the beginning of your upkeep, integrate the top card of target player's library.
Whenever a creature card is integrated onto Offerings to Sky Gods, create a 1/1 colorless Cyborg artifact creature token.

Ominous Quag enters tapped.
{T}: Add {W} or {B}.
{2}{W}{B}, {T}, Sacrifice Ominous Quag: Draw a card.

Whenever Omnoid Destroyer or another artifact you control enters, artifact creatures you control gain deathtouch until end of turn.

Open Air Boardwalk enters tapped.
{T}: Add {G} or {W}.
{4}: Make a pledge. Activate only as a sorcery.

Ozzen Headquarters enters tapped.
{T}: Add {W} or {B}.
{T}, Discard another card named Ozzen Headquarters: Draw a card.

Penrath District enters tapped unless you control a Mountain, a Forest, and a Plains.
{T}: Add {R}, {G}, or {W}.

{T}: Add one mana of any color.
{1}{VP}{VP}{VP}, {T}, Sacrifice Petabyte Prism: Draw two cards.