{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.

Cast this spell only during your turn.
Target creature gets +2/+0 and gains haste until end of turn. If it's attacking, instead it gets +2/+0 and gains trample until end of turn.
Flashback {1}{R}

Target creature gains first strike and gets +X/+0 until end of turn, where X is your devotion to red.

Whenever Music Master attacks, you may pay {U}. If you do, put a curio counter on another target creature you control.
{1}{U}: Target creature gains flying until end of turn.

When Mystery Egg enters, search your library for a card and exile it face down, then shuffle your library. You may look at that card as long as it remains exiled.
{G}, {T}, Sacrifice Mystery Egg: Turn the exiled card face up. You may cast that card this turn if it's a creature spell, and you may cast that spell as though it had flash.

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.

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.

Whenever another creature you control enters, Nomad's Companion gets +1/+1 until end of turn.

Destroy target creature if it has fewer colors than the number of colors of mana spent to cast this spell.

Enchant creature
Enchanted creature has “Whenever this creature deals combat damage to a player or planeswalker, scry 1, then draw a card.”

Trample
Amity — Whenever Old-Growth Gecko attacks, put a +1/+1 counter on another creature you control. If exactly one other creature attacked with it, this ability triggers three times instead.

Flying, first strike, lifelink
Landfall — Whenever a land you control enters, other creatures you control get +2/+2 until end of turn.

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

Your maximum hand size is zero.
Pay 1 life: Draw a card. Activate only as a sorcery.

When Opal-Eye Caretaker enters, put a +1/+1 counter on each creature you control that entered this turn and wasn't cast from your hand.
Wander {1}{W}

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.

When Pathetic Cocoon enters or dies, create a Berry token.

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