Colossal Majesty

At the beginning of your upkeep, if you control a creature with power 4 or greater, draw a card.

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, World Render

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

Counterspell

Thrakkus the Butcher

Trample
Whenever Thrakkus the Butcher attacks, double the power of each Dragon you control until end of turn.

Diabolic Tutor

Search your library for a card, put that card into your hand, then shuffle.

Tiamat

Flying
When Tiamat enters the battlefield, if you cast it, search your library for up to five Dragon cards not named Tiamat that each have different names, reveal them, put them into your hand, then shuffle.

Ramos, Dragon Engine

Flying
Whenever you cast a spell, put a +1/+1 counter on Ramos, Dragon Engine for each of that spell's colors.
Remove five +1/+1 counters from Ramos: Add {W}{W}{U}{U}{B}{B}{R}{R}{G}{G}. Activate only once each turn.

Terminate

Destroy target creature. It can't be regenerated.

Sivitri, Dragon Master

+1: Until your next turn, creatures can't attack you or planeswalkers you control unless their controller pays 2 life for each of those creatures.
−3: Search your library for a Dragon card, reveal it, put it into your hand, then shuffle.
−7: Destroy all non-Dragon creatures.
Sivitri, Dragon Master can be your commander.

Gemstone Mine

Gemstone Mine enters the battlefield with three mining counters on it.
{T}, Remove a mining counter from Gemstone Mine: Add one mana of any color. If there are no mining counters on Gemstone Mine, sacrifice it.

Dragonlord's Servant

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

Triskaidekaphile

You have no maximum hand size.
At the beginning of your upkeep, if you have exactly thirteen cards in your hand, you win the game.
{3}{U}: Draw a card.

Mortify

Nature's Lore

Search your library for a Forest card, put that card onto the battlefield, then shuffle.

Dragonspeaker Shaman

Dragon spells you cast cost {2} less to cast.

Blasphemous Act

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

Tamiyo's Safekeeping

Target permanent you control gains hexproof and indestructible until end of turn. You gain 2 life. (A permanent with hexproof and indestructible can't be the target of spells or abilities your opponents control. Damage and effects that say "destroy" don't destroy it.)

Supreme Verdict

This spell can't be countered.
Destroy all creatures.

Mountain

Utopia Tree

Swamp

Vampiric Tutor

Search your library for a card, then shuffle and put that card on top. You lose 2 life.

Sol Ring

Bloom Tender

{T}: For each color among permanents you control, add one mana of that color.

Plains

Dragon Arch

{2}, {T}: You may put a multicolored creature card from your hand onto the battlefield.

Sarkhan, Soul Aflame

Dragon spells you cast cost {1} less to cast.
Whenever a Dragon enters the battlefield under your control, you may have Sarkhan, Soul Aflame 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.

Elemental Bond

Whenever a creature with power 3 or greater enters the battlefield under your control, draw a card.

Thought Vessel

You have no maximum hand size.
{T}: Add {C}.

Psychic Strike

Counter target spell. Its controller mills two cards.

Reliquary Tower

Lathliss, Dragon Queen

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

Swords to Plowshares

Exile target creature. Its controller gains life equal to its power.

Negate

Forest

Terror of the Peaks

Flying
Spells your opponents cast that target Terror of the Peaks cost an additional 3 life to cast.
Whenever another creature enters the battlefield under your control, Terror of the Peaks deals damage equal to that creature's power to any target.

Dream Fracture

Counter target spell. Its controller draws a card.
Draw a card.

Teferi's Protection

Until your next turn, your life total can't change and you gain protection from everything. All permanents you control phase out. (While they're phased out, they're treated as though they don't exist. They phase in before you untap during your untap step.)
Exile Teferi's Protection.

Cancel

Demonic Tutor

Heroic Intervention

Permanents you control gain hexproof and indestructible until end of turn.

Earthquake

Earthquake deals X damage to each creature without flying and each player.

Island

Grim Tutor

Search your library for a card, put that card into your hand, then shuffle. You lose 3 life.

Crux of Fate

Choose one —
• Destroy all Dragon creatures.
• Destroy all non-Dragon creatures.

Farewell

Choose one or more —
• Exile all artifacts.
• Exile all creatures.
• Exile all enchantments.
• Exile all graveyards.

Farseek

Search your library for a Plains, Island, Swamp, or Mountain card, put it onto the battlefield tapped, then shuffle.

Flawless Maneuver

If you control a commander, you may cast this spell without paying its mana cost.
Creatures you control gain indestructible until end of turn.

Make a Stand

Creatures you control get +1/+0 and gain indestructible until end of turn. (Damage and effects that say "destroy" don't destroy them.)

Worldly Tutor

Search your library for a creature card, reveal it, then shuffle and put the card on top.

Ignoble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {B}, {R}, or {G}.

Jeweled Lotus

{T}, Sacrifice Jeweled Lotus: Add three mana of any one color. Spend this mana only to cast your commander.

Herald's Horn

As Herald's Horn enters the battlefield, choose a creature type.
Creature spells you cast of the chosen type cost {1} less to cast.
At the beginning of your upkeep, look at the top card of your library. If it's a creature card of the chosen type, you may reveal it and put it into your hand.

Saw It Coming

Counter target spell.
Foretell {1}{U} (During your turn, you may pay {2} and exile this card from your hand face down. Cast it on a later turn for its foretell cost.)

Ancient Silver Dragon

Flying
Whenever Ancient Silver Dragon deals combat damage to a player, roll a d20. Draw cards equal to the result. You have no maximum hand size for the rest of the game.

Acolyte of Bahamut

Commander creatures you own have "The first Dragon spell you cast each turn costs {2} less to cast."

Miirym, Sentinel Wyrm

Flying, ward {2}
Whenever another nontoken Dragon enters the battlefield under your control, create a token that's a copy of it, except the token isn't legendary.

Noble Hierarch

Exalted (Whenever a creature you control attacks alone, that creature gets +1/+1 until end of turn.)
{T}: Add {G}, {W}, or {U}.

Disruption Protocol

As an additional cost to cast this spell, tap an untapped artifact you control or pay {1}.
Counter target spell.

Delighted Halfling

{T}: Add {C}.
{T}: Add one mana of any color. Spend this mana only to cast a legendary spell, and that spell can't be countered.

Rampant Growth

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

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.

Scourge of Valkas

Flying
Whenever Scourge of Valkas or another Dragon enters the battlefield under your control, 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.

Mana Drain

Counter target spell. At the beginning of your next main phase, add an amount of {C} equal to that spell's mana value.

Temple of the False God

{T}: Add {C}{C}. Activate only if you control five or more lands.

Rootborn Defenses

Populate. Creatures you control gain indestructible until end of turn. (To populate, create a token that's a copy of a creature token you control.)