Xenagos, God of Revels

Indestructible
As long as your devotion to red and green is less than seven, Xenagos isn't a creature.
At the beginning of combat on your turn, another target creature you control gains haste and gets +X/+X until end of turn, where X is that creature's power.

Timber Gorge

Timber Gorge enters tapped.
{T}: Add {R} or {G}.

Wrathful Red Dragon

Flying
Whenever a Dragon you control is dealt damage, it deals that much damage to any target that isn't a Dragon.

Cultivate

Search your library for up to two basic land cards, reveal those cards, put one onto the battlefield tapped and the other into your hand, then shuffle.

Dragonmaster Outcast

At the beginning of your upkeep, if you control six or more lands, create a 5/5 red Dragon creature token with flying.

Scaled Herbalist

{T}: You may put a land card from your hand onto the battlefield.

Natural Connection

Search your library for a basic land card, put it onto the battlefield tapped, then shuffle.

Mountain

Goblin Anarchomancer

Each spell you cast that's red or green costs {1} less to cast.

Sarkhan, Dragonsoul

+2: Sarkhan, Dragonsoul deals 1 damage to each opponent and each creature your opponents control.
−3: Sarkhan, Dragonsoul deals 4 damage to target player or planeswalker.
−9: Search your library for any number of Dragon creature cards, put them onto the battlefield, then shuffle.

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.

Decimate

Destroy target artifact, target creature, target enchantment, and target land. (You can't cast this spell unless you have legal choices for all its targets.)

Forest

Thunderbreak Regent

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

Balefire Dragon

Flying
Whenever Balefire Dragon deals combat damage to a player, it deals that much damage to each creature that player controls.

Lathliss, Dragon Queen

Flying
Whenever another nontoken Dragon you control enters, create a 5/5 red Dragon creature token with flying.
{1}{R}: Dragons you control get +1/+0 until end of turn.

Slumbering Dragon

Flying
Slumbering Dragon can't attack or block unless it has five or more +1/+1 counters on it.
Whenever a creature attacks you or a planeswalker you control, put a +1/+1 counter on Slumbering Dragon.

Sarkhan, the Dragonspeaker

+1: Until end of turn, Sarkhan, the Dragonspeaker becomes a legendary 4/4 red Dragon creature with flying, indestructible, and haste. (He doesn't lose loyalty while he's not a planeswalker.)
−3: Sarkhan, the Dragonspeaker deals 4 damage to target creature.
−6: You get an emblem with "At the beginning of your draw step, draw two additional cards" and "At the beginning of your end step, discard your hand."

Ground Assault

Ground Assault deals damage to target creature equal to the number of lands you control.

Hull Breach

Choose one —
• Destroy target artifact.
• Destroy target enchantment.
• Destroy target artifact and target enchantment.

Drakuseth, Maw of Flames

Flying
Whenever Drakuseth attacks, it deals 4 damage to any target and 3 damage to each of up to two other targets.

Berserkers' Onslaught

Attacking creatures you control have double strike.

Samut, the Tested

+1: Up to one target creature gains double strike until end of turn.
−2: Samut, the Tested deals 2 damage divided as you choose among one or two targets.
−7: Search your library for up to two creature and/or planeswalker cards, put them onto the battlefield, then shuffle.

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.

Sarkhan, Fireblood

+1: You may discard a card. If you do, draw a card.
+1: Add two mana in any combination of colors. Spend this mana only to cast Dragon spells.
−7: Create four 5/5 red Dragon creature tokens with flying.

Ancient Bronze Dragon

Flying
Whenever Ancient Bronze Dragon deals combat damage to a player, roll a d20. When you do, put X +1/+1 counters on each of up to two target creatures, where X is the result.

Atarka, World Render

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

Nesting Dragon

Flying
Landfall — Whenever a land you control enters, create a 0/2 red Dragon Egg creature token with defender and "When this creature dies, create a 2/2 red Dragon creature token with flying and '{R}: This creature gets +1/+0 until end of turn.'"

Chaos Dragon

Flying, haste
Chaos Dragon attacks each combat if able.
At the beginning of combat on your turn, each player rolls a d20. If one or more opponents had the highest result, Chaos Dragon can't attack those players or planeswalkers they control this combat.

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 Muralists

When Draconic Muralists dies, you may search your library for a Dragon card, reveal it, put it into your hand, then shuffle.

Sarkhan Vol

+1: Creatures you control get +1/+1 and gain haste until end of turn.
−2: Gain control of target creature until end of turn. Untap that creature. It gains haste until end of turn.
−6: Create five 4/4 red Dragon creature tokens with flying.