Gate Colossus

This spell costs {1} less to cast for each Gate you control.
This creature can't be blocked by creatures with power 2 or less.
Whenever a Gate you control enters, you may put this card from your graveyard on top of your library.

Gatebreaker Ram

Gatebreaker Ram gets +1/+1 for each Gate you control.
As long as you control two or more Gates, Gatebreaker Ram has vigilance and trample.

Explore

You may play an additional land this turn.
Draw a card.

Guild Summit

When Guild Summit enters, you may tap any number of untapped Gates you control. Draw a card for each Gate tapped this way.
Whenever a Gate you control enters, draw a card.

Selesnya Guildgate

This land enters tapped.
{T}: Add {G} or {W}.

Gatecreeper Vine

Defender
When Gatecreeper Vine enters, you may search your library for a basic land card or a Gate card, reveal it, put it into your hand, then shuffle.

Forest

Gates Ablaze

Gates Ablaze deals X damage to each creature, where X is the number of Gates you control.

Gruul Guildgate

This land enters tapped.
{T}: Add {R} or {G}.

Plaza of Harmony

When Plaza of Harmony enters, if you control two or more Gates, you gain 3 life.
{T}: Add {C}.
{T}: Add one mana of any type that a Gate you control could produce.

Simic Guildgate

This land enters tapped.
{T}: Add {G} or {U}.

Zendikar Incarnate

Zendikar Incarnate's power is equal to the number of lands you control.

Spelunking

When Spelunking enters, draw a card, then you may put a land card from your hand onto the battlefield. If you put a Cave onto the battlefield this way, you gain 4 life.
Lands you control enter untapped.

Arboreal Grazer

Reach
When Arboreal Grazer enters, you may put a land card from your hand onto the battlefield tapped.

Golgari Guildgate

This land enters tapped.
{T}: Add {B} or {G}.

Izzet Guildgate

This land enters tapped.
{T}: Add {U} or {R}.

Baldur's Gate

{T}: Add {C}.
{2}, {T}: Add X mana of any one color, where X is the number of other Gates you control.