Gruul Guildgate

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

Intervention Pact

The next time a source of your choice would deal damage to you this turn, prevent that damage. You gain life equal to the damage prevented this way.
At the beginning of your next upkeep, pay {1}{W}{W}. If you don't, you lose the game.

Boros Guildgate

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

Summoner's Pact

Search your library for a green creature card, reveal it, put it into your hand, then shuffle.
At the beginning of your next upkeep, pay {2}{G}{G}. If you don't, you lose the game.

Orzhov Guildgate

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

Maze's End

This land enters tapped.
{T}: Add {C}.
{3}, {T}, Return this land to its owner's hand: Search your library for a Gate card, put it onto the battlefield, then shuffle. If you control ten or more Gates with different names, you win the game.

Child of Alara

Trample
When Child of Alara dies, destroy all nonland permanents. They can't be regenerated.

Simic Guildgate

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

Rakdos Guildgate

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

Pact of Negation

Counter target spell.
At the beginning of your next upkeep, pay {3}{U}{U}. If you don't, you lose the game.

Selesnya Guildgate

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

Pact of the Serpent

Choose a creature type. Target player draws X cards and loses X life, where X is the number of creatures they control of the chosen type.

Dimir Guildgate

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

Golgari Guildgate

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

Gateway Plaza

Gateway Plaza enters tapped.
When Gateway Plaza enters, sacrifice it unless you pay {1}.
{T}: Add one mana of any color.

Pact of the Titan

Create a 4/4 red Giant creature token.
At the beginning of your next upkeep, pay {4}{R}. If you don't, you lose the game.

Slaughter Pact

Destroy target nonblack creature.
At the beginning of your next upkeep, pay {2}{B}. If you don't, you lose the game.

Izzet Guildgate

Izzet Guildgate enters tapped.
{T}: Add {U} or {R}.

Hive Mind

Whenever a player casts an instant or sorcery spell, each other player copies that spell. Each of those players may choose new targets for their copy.