Overwhelming Stampede

Until end of turn, creatures you control gain trample and get +X/+X, where X is the greatest power among creatures you control.

Thrakkus the Butcher

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

Miirym, Sentinel Wyrm

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

Chaos Warp

The owner of target permanent shuffles it into their library, then reveals the top card of their library. If it's a permanent card, they put it onto the battlefield.

Herald's Horn

As Herald's Horn enters, 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.

Disrupt

Counter target instant or sorcery spell unless its controller pays {1}.
Draw a card.

Bear Umbra

Enchant creature
Enchanted creature gets +2/+2 and has "Whenever this creature attacks, untap all lands you control."
Umbra armor (If enchanted creature would be destroyed, instead remove all damage from it and destroy this Aura.)

Hoarding Dragon

Flying
When this creature enters, you may search your library for an artifact card, exile it, then shuffle.
When this creature dies, you may put the exiled card into its owner's hand.

Rofellos, Llanowar Emissary

{T}: Add {G} for each Forest you control.

Lozhan, Dragons' Legacy

Flying
Whenever you cast an Adventure or Dragon spell, Lozhan, Dragons' Legacy deals damage equal to that spell's mana value to any target that isn't a commander.

Junk Diver

Flying
When Junk Diver dies, return another target artifact card from your graveyard to your hand.

Mimic Vat

Imprint — Whenever a nontoken creature dies, you may exile that card. If you do, return each other card exiled with Mimic Vat to its owner's graveyard.
{3}, {T}: Create a token that's a copy of a card exiled with Mimic Vat. It gains haste. Exile it at the beginning of the next end step.

Blur

Exile target creature you control, then return that card to the battlefield under its owner's control.
Draw a card.

Negate

Scaled Nurturer

{T}: Add {G}. When you spend this mana to cast a Dragon creature spell, you gain 2 life.

Jeska's Will

Choose one. If you control a commander as you cast this spell, you may choose both instead.
• Add {R} for each card in target opponent's hand.
• Exile the top three cards of your library. You may play them this turn.

Firkraag, Cunning Instigator

Flying, haste
Whenever one or more Dragons you control attack an opponent, goad target creature that player controls.
Whenever a creature deals combat damage to one of your opponents, if that creature had to attack this combat, you put a +1/+1 counter on Firkraag, Cunning Instigator and you draw a card.

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.

The Apprentice's Folly

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I, II — Choose target nontoken creature you control that doesn't have the same name as a token you control. Create a token that's a copy of it, except it isn't legendary, is a Reflection in addition to its other types, and has haste.
III — Sacrifice all Reflections you control.

Island

Cavern-Hoard Dragon

This spell costs {X} less to cast, where X is the greatest number of artifacts an opponent controls.
Flying, trample, haste
Whenever Cavern-Hoard Dragon deals combat damage to a player, you create a Treasure token for each artifact that player controls.

Skanos Dragonheart

Whenever Skanos Dragonheart attacks, it gets +X/+X until end of turn, where X is the greatest power among other Dragons you control and Dragon cards in your graveyard.
Choose a Background (You can have a Background as a second commander.)

Savage Ventmaw

Flying
Whenever this creature attacks, add {R}{R}{R}{G}{G}{G}. Until end of turn, you don't lose this mana as steps and phases end.

Gruul Cluestone

{T}: Add {R} or {G}.
{R}{G}, {T}, Sacrifice Gruul Cluestone: Draw a card.

Boompile

{T}: Flip a coin. If you win the flip, destroy all nonland permanents.

Spark Double

You may have Spark Double enter as a copy of a creature or planeswalker you control, except it enters with an additional +1/+1 counter on it if it's a creature, it enters with an additional loyalty counter on it if it's a planeswalker, and it isn't legendary.

Forest

Blasphemous Act

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

Bonehoard Dracosaur

Flying, first strike
At the beginning of your upkeep, exile the top two cards of your library. You may play them this turn. If you exiled a land card this way, create a 3/1 red Dinosaur creature token. If you exiled a nonland card this way, create a Treasure token.

Glasses of Urza

Bane of Progress

When Bane of Progress enters, destroy all artifacts and enchantments. Put a +1/+1 counter on Bane of Progress for each permanent destroyed this way.

Silvanus's Invoker

Conjure Elemental — {8}: Untap target land you control. It becomes an 8/8 Elemental creature with trample and haste until end of turn. It's still a land.

Crucible of Fire

From the Ashes

Destroy all nonbasic lands. For each land destroyed this way, its controller may search their library for a basic land card and put it onto the battlefield. Then each player who searched their library this way shuffles.

Nimbleclaw Adept

Bigby's Hand — {T}: Untap two other target permanents. Activate only as a sorcery and only once each turn.

Abundant Growth

Enchant land
When Abundant Growth enters, draw a card.
Enchanted land has "{T}: Add one mana of any color."

Niv-Mizzet, Parun

This spell can't be countered.
Flying
Whenever you draw a card, Niv-Mizzet, Parun deals 1 damage to any target.
Whenever a player casts an instant or sorcery spell, you draw a card.

Twinflame Tyrant

Flying
If a source you control would deal damage to an opponent or a permanent an opponent controls, it deals double that damage instead.

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.

There and Back Again

(As this Saga enters and after your draw step, add a lore counter. Sacrifice after III.)
I — Up to one target creature can't block for as long as you control There and Back Again. The Ring tempts you.
II — Search your library for a Mountain card, put it onto the battlefield, then shuffle.
III — Create Smaug, a legendary 6/6 red Dragon creature token with flying, haste, and "When this creature dies, create fourteen Treasure tokens."

Chromatic Lantern

Lands you control have "{T}: Add one mana of any color."
{T}: Add one mana of any color.

Mountain

Dissenter's Deliverance

Destroy target artifact.
Cycling {G} ({G}, Discard this card: Draw a card.)

Mirage Mirror

{2}: Mirage Mirror becomes a copy of target artifact, creature, enchantment, or land until end of turn.

Thran Dynamo

Elvish Piper

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

Korlessa, Scale Singer

You may look at the top card of your library any time.
You may cast Dragon spells from the top of your library.

Sol Ring

Niv-Mizzet, Visionary

Flying
You have no maximum hand size.
Whenever a source you control deals noncombat damage to an opponent, you draw that many cards.

Commander's Sphere

{T}: Add one mana of any color in your commander's color identity.
Sacrifice Commander's Sphere: Draw a card.

Day of the Dragons

When Day of the Dragons enters, exile all creatures you control. Then create that many 5/5 red Dragon creature tokens with flying.
When Day of the Dragons leaves the battlefield, sacrifice all Dragons you control. Then return the exiled cards to the battlefield under your control.

Llanowar Elves

Old Gnawbone

Flying
Whenever a creature you control deals combat damage to a player, create that many Treasure tokens.

Klauth, Unrivaled Ancient

Flying, haste
Whenever Klauth, Unrivaled Ancient attacks, add X mana in any combination of colors, where X is the total power of attacking creatures. Spend this mana only to cast spells. Until end of turn, you don't lose this mana as steps and phases end.

Intet, the Dreamer

Flying
Whenever Intet, the Dreamer deals combat damage to a player, you may pay {2}{U}. If you do, exile the top card of your library face down. You may look at that card for as long as it remains exiled. You may play that card without paying its mana cost for as long as Intet remains on the battlefield.

Brainstorm

Draw three cards, then put two cards from your hand on top of your library in any order.

Decree of Annihilation

Exile all artifacts, creatures, and lands from the battlefield, all cards from all graveyards, and all cards from all hands.
Cycling {5}{R}{R} ({5}{R}{R}, Discard this card: Draw a card.)
When you cycle Decree of Annihilation, destroy all lands.

Filigree Fracture

Destroy target artifact or enchantment. If that permanent was blue or black, draw a card.

Demand Answers

As an additional cost to cast this spell, sacrifice an artifact or discard a card.
Draw two cards.

Expedite

Target creature gains haste until end of turn.
Draw a card.

Balefire Dragon

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

Niv-Mizzet, the Firemind

Flying
Whenever you draw a card, Niv-Mizzet, the Firemind deals 1 damage to any target.
{T}: Draw a card.

Faithless Looting

Draw two cards, then discard two cards.
Flashback {2}{R} (You may cast this card from your graveyard for its flashback cost. Then exile it.)

Benefactor's Draught

Untap all creatures. Until end of turn, whenever a creature an opponent controls blocks, draw a card.
Draw a card.