Haven of the Spirit Dragon

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a Dragon creature spell.
{2}, {T}, Sacrifice Haven of the Spirit Dragon: Return target Dragon creature card or Ugin planeswalker card from your graveyard to your hand.

Atarka Monument

{T}: Add {R} or {G}.
{4}{R}{G}: Atarka Monument becomes a 4/4 red and green Dragon artifact creature with flying until end of turn.

Rageform

When Rageform enters the battlefield, it becomes an Aura with enchant creature. Manifest the top card of your library and attach Rageform to it. (To manifest a card, put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)
Enchanted creature has double strike. (It deals both first-strike and regular combat damage.)

Atarka, World Render

Flying, trample
Whenever a Dragon you control attacks, it gains double strike until end of turn.

Whisperer of the Wilds

{T}: Add {G}.
Ferocious — {T}: Add {G}{G}. Activate only if you control a creature with power 4 or greater.

Rage Reflection

Creatures you control have double strike.

Surrak, the Hunt Caller

Formidable — At the beginning of combat on your turn, if creatures you control have total power 8 or greater, target creature you control gains haste until end of turn.

Rugged Highlands

Rugged Highlands enters the battlefield tapped.
When Rugged Highlands enters the battlefield, you gain 1 life.
{T}: Add {R} or {G}.

Lurking Arynx

Formidable — {2}{G}: Target creature blocks Lurking Arynx this turn if able. Activate only if creatures you control have total power 8 or greater.

Snow-Covered Mountain

Tread Upon

Target creature gets +2/+2 and gains trample until end of turn.

Circle of Elders

Vigilance
Formidable — {T}: Add {C}{C}{C}. Activate only if creatures you control have total power 8 or greater.

Ugin's Construct

When Ugin's Construct enters the battlefield, sacrifice a permanent that's one or more colors.

Roar of Challenge

All creatures able to block target creature this turn do so.
Ferocious — That creature gains indestructible until end of turn if you control a creature with power 4 or greater.

Destructor Dragon

Flying
When Destructor Dragon dies, destroy target noncreature permanent.

See the Unwritten

Reveal the top eight cards of your library. You may put a creature card from among them onto the battlefield. Put the rest into your graveyard.
Ferocious — If you control a creature with power 4 or greater, you may put two creature cards onto the battlefield instead of one.

Conifer Strider

Hexproof (This creature can't be the target of spells or abilities your opponents control.)

Crater's Claws

Crater's Claws deals X damage to any target.
Ferocious — Crater's Claws deals X plus 2 damage instead if you control a creature with power 4 or greater.

Sheltered Aerie

Enchant land
Enchanted land has "{T}: Add two mana of any one color."

Commune with Lava

Exile the top X cards of your library. Until the end of your next turn, you may play those cards.

Dragon Tempest

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

Heir of the Wilds

Deathtouch
Ferocious — Whenever Heir of the Wilds attacks, if you control a creature with power 4 or greater, Heir of the Wilds gets +1/+1 until end of turn.

Sabertooth Outrider

Trample
Formidable — Whenever Sabertooth Outrider attacks, if creatures you control have total power 8 or greater, Sabertooth Outrider gains first strike until end of turn.

Goblinslide

Whenever you cast a noncreature spell, you may pay {1}. If you do, create a 1/1 red Goblin creature token with haste.

Feed the Clan

You gain 5 life.
Ferocious — You gain 10 life instead if you control a creature with power 4 or greater.

Flamewake Phoenix

Flying, haste
Flamewake Phoenix attacks each combat if able.
Ferocious — At the beginning of combat on your turn, if you control a creature with power 4 or greater, you may pay {R}. If you do, return Flamewake Phoenix from your graveyard to the battlefield.

Furnace of Rath

If a source would deal damage to a permanent or player, it deals double that damage to that permanent or player instead.

Assault Formation

Each creature you control assigns combat damage equal to its toughness rather than its power.
{G}: Target creature with defender can attack this turn as though it didn't have defender.
{2}{G}: Creatures you control get +0/+1 until end of turn.

Frontier Siege

As Frontier Siege enters the battlefield, choose Khans or Dragons.
• Khans — At the beginning of each of your main phases, add {G}{G}.
• Dragons — Whenever a creature with flying enters the battlefield under your control, you may have it fight target creature you don't control.

Mana Reflection

If you tap a permanent for mana, it produces twice as much of that mana instead.

Seismic Rupture

Seismic Rupture deals 2 damage to each creature without flying.

Atarka Efreet

Megamorph {2}{R} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)
When Atarka Efreet is turned face up, it deals 1 damage to any target.

Wild Slash

Ferocious — If you control a creature with power 4 or greater, damage can't be prevented this turn.
Wild Slash deals 2 damage to any target.

Ugin's Nexus

If a player would begin an extra turn, that player skips that turn instead.
If Ugin's Nexus would be put into a graveyard from the battlefield, instead exile it and take an extra turn after this one.

Dragonlord's Servant

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

Atarka Beastbreaker

Formidable — {4}{G}: Atarka Beastbreaker gets +4/+4 until end of turn. Activate only if creatures you control have total power 8 or greater.

Barrage of Boulders

Barrage of Boulders deals 1 damage to each creature you don't control.
Ferocious — If you control a creature with power 4 or greater, creatures can't block this turn.

Crucible of the Spirit Dragon

{T}: Add {C}.
{1}, {T}: Put a storage counter on Crucible of the Spirit Dragon.
{T}, Remove X storage counters from Crucible of the Spirit Dragon: Add X mana in any combination of colors. Spend this mana only to cast Dragon spells or activate abilities of Dragons.

Dragonlord Atarka

Flying, trample
When Dragonlord Atarka enters the battlefield, it deals 5 damage divided as you choose among any number of target creatures and/or planeswalkers your opponents control.

Tail Slash

Target creature you control deals damage equal to its power to target creature you don't control.

Dragon-Scarred Bear

Formidable — {1}{G}: Regenerate Dragon-Scarred Bear. Activate only if creatures you control have total power 8 or greater.

Shaman of Forgotten Ways

{T}: Add two mana in any combination of colors. Spend this mana only to cast creature spells.
Formidable — {9}{G}{G}, {T}: Each player's life total becomes the number of creatures they control. Activate only if creatures you control have total power 8 or greater.

Atarka's Command

Choose two —
• Your opponents can't gain life this turn.
• Atarka's Command deals 3 damage to each opponent.
• You may put a land card from your hand onto the battlefield.
• Creatures you control get +1/+1 and gain reach until end of turn.

Dragon Grip

Ferocious — If you control a creature with power 4 or greater, you may cast Dragon Grip as though it had flash. (You may cast it any time you could cast an instant.)
Enchant creature
Enchanted creature gets +2/+0 and has first strike.

Glade Watcher

Defender
Formidable — {G}: Glade Watcher can attack this turn as though it didn't have defender. Activate only if creatures you control have total power 8 or greater.

Ugin, the Spirit Dragon

+2: Ugin, the Spirit Dragon deals 3 damage to any target.
−X: Exile each permanent with mana value X or less that's one or more colors.
−10: You gain 7 life, draw seven cards, then put up to seven permanent cards from your hand onto the battlefield.

Magmatic Chasm

Creatures without flying can't block this turn.

Temur Battle Rage

Target creature gains double strike until end of turn.
Ferocious — That creature also gains trample until end of turn if you control a creature with power 4 or greater.

Hardened Berserker

Whenever Hardened Berserker attacks, the next spell you cast this turn costs {1} less to cast.

Evolving Wilds

{T}, Sacrifice Evolving Wilds: Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Dragon Fodder

Create two 1/1 red Goblin creature tokens.

Dragon Whisperer

{R}: Dragon Whisperer gains flying until end of turn.
{1}{R}: Dragon Whisperer gets +1/+0 until end of turn.
Formidable — {4}{R}{R}: Create a 4/4 red Dragon creature token with flying. Activate only if creatures you control have total power 8 or greater.

Volcanic Rush

Attacking creatures get +2/+0 and gain trample until end of turn.

Shamanic Revelation

Draw a card for each creature you control.
Ferocious — You gain 4 life for each creature you control with power 4 or greater.

Fruit of the First Tree

Enchant creature
When enchanted creature dies, you gain X life and draw X cards, where X is its toughness.

Fiery Emancipation

If a source you control would deal damage to a permanent or player, it deals triple that damage to that permanent or player instead.

Winds of Qal Sisma

Prevent all combat damage that would be dealt this turn.
Ferocious — If you control a creature with power 4 or greater, instead prevent all combat damage that would be dealt this turn by creatures your opponents control.

Crater Elemental

{R}, {T}, Sacrifice Crater Elemental: It deals 4 damage to target creature.
Formidable — {2}{R}: Crater Elemental has base power 8 until end of turn. Activate only if creatures you control have total power 8 or greater.

Harmonize

Stampeding Elk Herd

Formidable — Whenever Stampeding Elk Herd attacks, if creatures you control have total power 8 or greater, creatures you control gain trample until end of turn.

Savage Punch

Target creature you control fights target creature you don't control.
Ferocious — The creature you control gets +2/+2 until end of turn before it fights if you control a creature with power 4 or greater.

Atarka Pummeler

Formidable — {3}{R}{R}: Creatures you control gain menace until end of turn. Activate only if creatures you control have total power 8 or greater. (They can't be blocked except by two or more creatures.)

Blasphemous Act

This spell costs {1} less to cast for each creature on the battlefield.
Blasphemous Act deals 13 damage to each creature.

Roast

Roast deals 5 damage to target creature without flying.

Berserkers' Onslaught

Attacking creatures you control have double strike.

Harbinger of the Hunt

Flying
{2}{R}: Harbinger of the Hunt deals 1 damage to each creature without flying.
{2}{G}: Harbinger of the Hunt deals 1 damage to each other creature with flying.

Frontier Mastodon

Ferocious — Frontier Mastodon enters the battlefield with a +1/+1 counter on it if you control a creature with power 4 or greater.