Miirym is a Temur Dragon tribal deck that ramps hard and cuts the cost of big Dragons, then copies each one with Miirym so every Dragon enters twice. Miirym only copies another nontoken Dragon that enters under its controller, and the copy is non-legendary, so legendary Dragons get a usable twin. The doubled enter triggers power the deck: damage when Dragons enter, Treasure and token makers, card draw for big creatures, and Dragons that boost other Dragons. How it wins: The deck builds a wide air force of doubled Dragons, turns them into lethal damage with double strike, power doubling and haste, and burns players with enter and attack triggers, with Niv-Mizzet plus a damage-draw aura as an extra combo kill. Key roles: - Dragon cost reduction and creature ramp: Mana dorks, land auras and Dragon-only cost reducers and lands get six-drop Dragons and Miirym out early, then let several Dragons resolve in one turn. (Dragonspeaker Shaman, Somberwald Sage, Gwenna, Eyes of Gaea) - Enter-trigger payoffs: Each Dragon entering, and its Miirym copy, deals damage scaled by the number of Dragons, makes Treasure, or adds extra 5/5 Dragon tokens, so every cast hits twice. (Scourge of Valkas, Dragon Tempest, Lathliss, Dragon Queen) - Clone and copy doubling: Copy effects turn a strong Dragon into extra copies. A Frostkite copy counts as a nontoken Dragon entering, so Miirym copies it too, and flicker effects re-trigger both Miirym and enter abilities. (Spark Double, Deceptive Frostkite, Ghostly Flicker) - Big-creature card flow: Enchantments and Dragons that draw or cast from the top of the library whenever a power 4 or greater creature enters keep the hand full of Dragons. Miirym's copies double those triggers. (Garruk's Uprising, Temur Ascendancy, Thundermane Dragon) - Combat amplifiers and haste: Haste, double strike and power doubling turn a board of fliers into a one-turn kill, and attack triggers add mana, burn and extra value. (Atarka, World Render, Thrakkus the Butcher, Savage Ventmaw) - Niv-Mizzet damage-draw engine: An aura that draws on damage, placed on Niv-Mizzet, makes each draw ping an opponent and draw again, looping into near-infinite damage. Damage-draw creatures like Dragonborn Champion add more draws in combat. (Niv-Mizzet, Parun, Curiosity, Keen Sense)

Miirym, Sentinel Wyrm decklist

• Arcane Denial
• Arcane Signet
• Atarka, World Render
• Atsushi, the Blazing Sky
• Beast Within
• Blasphemous Act
• Cascade Bluffs
• Chaos Warp
• Cinder Glade
• Command Tower
• Counterspell
• Curiosity
• Deceptive Frostkite
• Dragon Broodmother
• Dragon Tempest
• Dragonborn Champion
• Dragonhawk, Fate's Tempest
• Dragonlord Atarka
• Dragonlord's Servant
• Dragonspeaker Shaman
• Dreamroot Cascade
• Elemental Bond
• Elvish Mystic
• Evolution Charm
• Exotic Orchard
• Farseek
• Fiery Islet
• Fire-Lit Thicket
• Flooded Grove
• 5× Forest
• Frontier Bivouac
• Frostboil Snarl
• Ganax, Astral Hunter
• Garruk's Uprising
• Ghostly Flicker
• Goldspan Dragon
• Gwenna, Eyes of Gaea
• Haven of the Spirit Dragon
• Hellkite Courser
• Herald's Horn
• Highland Forest
• Hinterland Harbor
• 3× Island
• Karplusan Forest
• Keen Sense
• Lathliss, Dragon Queen
• Leyline Tyrant
• Llanowar Elves
• Lozhan, Dragons' Legacy
• Maelstrom of the Spirit Dragon
• Marang River Regent
• 2× Mountain
• Nature's Lore
• Niv-Mizzet, Parun
• Parapet Thrasher
• Path of Ancestry
• Pongify
• Realmwalker
• Return of the Wildspeaker
• Rimewood Falls
• Rockfall Vale
• Rootbound Crag
• Sakura-Tribe Elder
• Sarkhan, Soul Aflame
• Sarkhan's Triumph
• Savage Ventmaw
• Scaled Nurturer
• Scourge of Valkas
• Secluded Courtyard
• Shivan Reef
• Smaug the Magnificent
• Smuggler's Surprise
• Sol Ring
• Somberwald Sage
• Spark Double
• Stormcarved Coast
• Sulfur Falls
• Swiftfoot Boots
• Talisman of Creativity
• Temur Ascendancy
• Thrakkus the Butcher
• Thunderbreak Regent
• Thundermane Dragon
• Utopia Sprawl
• Vandalblast
• Veil of Summer
• Vineglimmer Snarl
• Volatile Fjord
• Waterlogged Grove
• Wild Growth
• Wrathful Red Dragon
• Yavimaya Coast