You can obtain the Mega Diancie ex (4-Diamonds rarity) card by opening Everyday Wonders from Everyday Wonders set
Like whether you want MTGA to auto-tap lands for mana, for example

A Trail of Teacups Aberrant Researcher Acolyte of Affliction Admiral Brass, Unsinkable Advanced Reconstruction Aftermath Analyst Ainok Wayfarer Airlift Chaplain Altar of the Wretched Angel of Suffering Another Chance Anowon, the Ruin Thief Argoth, Sanctum of Nature Ark of Hunger Armored Skaab Ashcoat of the Shadow Swarm Ashcoat of the Shadow Swarm Atrocious Experiment Autumnal Gloom Avatar Destiny Aven Heartstabber Awaken the Honored Dead Ballad of the Black Flag Bane-Marked Leonin Barrowgoyf Belltower Sphinx Beluna Grandsquall Beluna Grandsquall Billowing Shriekmass Black Widow, Daring Operative Blanchwood Prowler Blight Titan Blood Spatter Analysis Bloodcurdler Blossoming Tortoise Bramble Familiar Bramble Familiar Bristlebud Farmer Bruvac the Grandiloquent Burrowing Razormaw Cache Grab Carrion Cruiser Carrion Grub Cauldron's Gift Cemetery Tampering Cephalid Aristocrat Cephalid Illusionist Cephalid Vandal Chains of Mephistopheles Charmed Pendant Circle of the Land Druid Cloudhoof Kirin Colossal Badger Colossal Badger Colossal Grave-Reaver Combustible Gearhulk Convergence of Dominion Coral Colony Corpse Churn Court of Cunning Covetous Castaway Crawling Infestation Crawling Sensation Crop Sigil Crow of Dark Tidings Daggerfang Duo Dakmor Salvage Darkblast Dawnhand Eulogist Deadbridge Chant Death's Oasis Deathbonnet Sprout

Flexibility like that is exactly what lets slower dragon decks keep up with faster, more consistent strategies
Even if an OTK going second seems difficult, if you deal some damage by attacking with "Superdreadnought Rail Cannon Superior Dora," which has good field presence, there are many patterns where you can finish them off even if the opponent builds a board on the next turn
CONSISTS OF: - 1 Vintage Holographic Card