Pillar of Origins

As this artifact 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.

Demanding Dragon

Flying
When this creature enters, it deals 5 damage to target opponent unless that player sacrifices a creature of their choice.

Terror of the Peaks

Flying
Spells your opponents cast that target this creature cost an additional 3 life to cast.
Whenever another creature you control enters, this creature deals damage equal to that creature's power to any target.

Shivan Reef

{T}: Add {C}.
{T}: Add {U} or {R}. This land deals 1 damage to you.

Thunderbreak Regent

Flying
Whenever a Dragon you control becomes the target of a spell or ability an opponent controls, this creature deals 3 damage to that player.

Iymrith, Desert Doom

Flying
Iymrith has ward {4} as long as it's untapped.
Whenever Iymrith deals combat damage to a player, draw a card. Then if you have fewer than three cards in hand, draw cards equal to the difference.

Mountain

Atsushi, the Blazing Sky

Flying, trample
When Atsushi dies, choose one —
• Exile the top two cards of your library. Until the end of your next turn, you may play those cards.
• Create three Treasure tokens.

Defiant Thundermaw

Flying, trample
Whenever a Dragon you control attacks, it deals 2 damage to any target.

Invasion of Tarkir

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When this Siege enters, reveal any number of Dragon cards from your hand. When you do, this Siege deals X plus 2 damage to any other target, where X is the number of cards revealed this way. (X can be 0.)

Invasion of Tarkir // Defiant Thundermaw

Spirebluff Canal

This land enters tapped unless you control two or fewer other lands.
{T}: Add {U} or {R}.

Island

Sarkhan, Soul Aflame

Dragon spells you cast cost {1} less to cast.
Whenever a Dragon you control enters, you may have Sarkhan become a copy of it until end of turn, except its name is Sarkhan, Soul Aflame and it's legendary in addition to its other types.

Spell Pierce

Counter target noncreature spell unless its controller pays {2}.

Steam Vents

({T}: Add {U} or {R}.)
As this land enters, you may pay 2 life. If you don't, it enters tapped.

Stubborn Denial

Counter target noncreature spell unless its controller pays {1}.
Ferocious — If you control a creature with power 4 or greater, counter that spell instead.

Sulfur Falls

This land enters tapped unless you control an Island or a Mountain.
{T}: Add {U} or {R}.

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.

Silumgar's Scorn

As an additional cost to cast this spell, you may reveal a Dragon card from your hand.
Counter target spell unless its controller pays {1}. If you revealed a Dragon card or controlled a Dragon as you cast this spell, counter that spell instead.

Valakut Stoneforge

Valakut Awakening

Put any number of cards from your hand on the bottom of your library, then draw that many cards plus one.