Miirym, Sentinel Wyrm runs a Temur Dragon tribal deck. Whenever another nontoken Dragon enters, Miirym makes a nonlegendary token copy of it under the player's control, so every Dragon's enter trigger fires twice and the board doubles. Dragon cost reducers and creature-only ramp let the deck chain big Dragons quickly. Haste enablers, power-4-or-greater card draw and Dragon "enters" damage engines turn each doubled Dragon into burn, cards and a lethal air force. How it wins: It overwhelms opponents with doubled flying Dragons, given haste and boosted by combat amplifiers like double strike and power doubling, plus stacked enter-the-battlefield damage, with the Niv-Mizzet, Parun and Curiosity or Keen Sense loop as an alternate instant kill. Key roles: - Dragon cost reduction and creature ramp: Mana dorks, Dragon-only or creature-only mana sources and tribal discounts get six- and seven-drop Dragons out early and let several land per turn, so Miirym can copy them. (Dragonspeaker Shaman, Somberwald Sage, Gwenna, Eyes of Gaea) - Enter-the-battlefield value doubled: Dragons with strong enter or "another Dragon enters" triggers get copied, so their bounce, burn, Treasure and token effects happen twice. Treasure from these triggers feeds more casting. (Dragonlord Atarka, Lathliss, Dragon Queen, Ganax, Astral Hunter) - Dragon-count burn: Every Dragon entering, token copies included, deals damage equal to the number of Dragons controlled. This stacks into reach and removal as the flock grows, and copies of Scourge each add another trigger. (Scourge of Valkas, Dragon Tempest, Wrathful Red Dragon) - Copy and clone amplifiers: Clones and copy effects duplicate the best Dragon or Miirym itself. Flicker effects reset nontoken Dragons so Miirym copies them again. (Spark Double, Sarkhan, Soul Aflame, Ghostly Flicker) - Big-body card advantage: Draw engines that trigger on creatures with power 3 or 4+ entering keep the hand full, since nearly every Dragon and token qualifies, often twice. (Garruk's Uprising, Temur Ascendancy, Elemental Bond) - Haste and combat finishers: Haste lets fresh copies swing at once, and attack-triggered double strike, power doubling and mana bursts turn a single attack into a kill. Niv-Mizzet with a draw-on-damage aura is a backup infinite loop. (Atarka, World Render, Thrakkus the Butcher, Niv-Mizzet, Parun)

Miirym, Sentinel Wyrm decklist

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