Boros Guildgate

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

Siege Dragon

Flying
When Siege Dragon enters, destroy all Walls your opponents control.
Whenever Siege Dragon attacks, if defending player controls no Walls, it deals 2 damage to each creature without flying that player controls.

Dragonlord's Servant

Dragon spells you cast cost {1} less to cast.

Mountain

Thundermaw Hellkite

Flying
Haste (This creature can attack and {T} as soon as it comes under your control.)
When Thundermaw Hellkite enters, it deals 1 damage to each creature with flying your opponents control. Tap those creatures.

Dragon Egg

Defender
When Dragon Egg dies, create a 2/2 red Dragon creature token with flying and "{R}: This creature gets +1/+0 until end of turn."

Furyborn Hellkite

Bloodthirst 6 (If an opponent was dealt damage this turn, this creature enters with six +1/+1 counters on it.)
Flying

Rakdos Guildgate

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

Ojutai, Soul of Winter

Flying, vigilance
Whenever a Dragon you control attacks, tap target nonland permanent an opponent controls. That permanent doesn't untap during its controller's next untap step.

Dragon Tempest

Whenever a creature you control with flying enters, it gains haste until end of turn.
Whenever a Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.

Glorybringer

Flying, haste
You may exert Glorybringer as it attacks. When you do, it deals 4 damage to target non-Dragon creature an opponent controls. (An exerted creature won't untap during your next untap step.)

Act of Aggression

({R/P} can be paid with either {R} or 2 life.)
Gain control of target creature an opponent controls until end of turn. Untap that creature. It gains haste until end of turn.

Wayfarer's Bauble

{2}, {T}, Sacrifice Wayfarer's Bauble: Search your library for a basic land card, put that card onto the battlefield tapped, then shuffle.

Cascading Cataracts

Indestructible
{T}: Add {C}.
{5}, {T}: Add five mana in any combination of colors.

Gruul Guildgate

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

Bogardan Hellkite

Flash
Flying
When Bogardan Hellkite enters, it deals 5 damage divided as you choose among any number of targets.

Pillar of Origins

As Pillar of Origins enters, choose a creature type.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell of the chosen type.

Spit Flame

Spit Flame deals 4 damage to target creature.
Whenever a Dragon you control enters, you may pay {R}. If you do, return Spit Flame from your graveyard to your hand.

Skyship Stalker

Flying
{R}: Skyship Stalker gets +1/+0 until end of turn.
{R}: Skyship Stalker gains first strike until end of turn.
{R}: Skyship Stalker gains haste until end of turn.

Belbe's Portal

As Belbe's Portal enters, choose a creature type.
{3}, {T}: You may put a creature card of the chosen type from your hand onto the battlefield.

Dragonlord Dromoka

This spell can't be countered.
Flying, lifelink
Your opponents can't cast spells during your turn.

Palladia-Mors, the Ruiner

Flying, vigilance, trample
Palladia-Mors, the Ruiner has hexproof if it hasn't dealt damage yet.

Sarkhan the Masterless

Whenever a creature attacks you or a planeswalker you control, each Dragon you control deals 1 damage to that creature.
+1: Until end of turn, each planeswalker you control becomes a 4/4 red Dragon creature and gains flying.
−3: Create a 4/4 red Dragon creature token with flying.

Draconic Roar

As an additional cost to cast this spell, you may reveal a Dragon card from your hand.
Draconic Roar deals 3 damage to target creature. If you revealed a Dragon card or controlled a Dragon as you cast this spell, Draconic Roar deals 3 damage to that creature's controller.

Scourge of Valkas

Flying
Whenever Scourge of Valkas or another Dragon you control enters, it deals X damage to any target, where X is the number of Dragons you control.
{R}: Scourge of Valkas gets +1/+0 until end of turn.

Thran Dynamo

Dragon's Hoard

Whenever a Dragon you control enters, put a gold counter on Dragon's Hoard.
{T}, Remove a gold counter from Dragon's Hoard: Draw a card.
{T}: Add one mana of any color.

Izzet Guildgate

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

Cryptic Gateway

Tap two untapped creatures you control: You may put a creature card from your hand that shares a creature type with each creature tapped this way onto the battlefield.

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.