A diverse set of Pokmon types requires a substantial number of energy cards for each type, significantly reducing space for essential Trainer cards and making your deck inconsistent
Enchantment Color tag templates(None) Claws of Valakut Enchant creature Enchanted creature gets +1/+0 for each Mountain you control and has first strike
We know how big of a difference a single mana can make

Hans, Run!" Agatha of the Vile Cauldron Alien Invasion Arbalest Engineers Arlinn Kord Arlinn, Embraced by the Moon Arlinn, the Moon's Fury Atalan Jackal Bello, Bard of the Brambles Bitter Work Blaster, Morale Booster Blitz Hellion Bloodbraid Challenger Bloodbraid Elf Boggart Ram-Gang Break Out Brushfire Elemental Cactusfolk Sureshot Charging War Boar Clan Guildmage Deathleaper, Terror Weapon Domri Rade Domri, Chaos Bringer Domri, City Smasher Esper Terra Fanatic of Xenagos Fires of Yavimaya Firewake Sliver Frenzied Arynx Gallia of the Endless Dance Giant Solifuge Giantbaiting Grand Warlord Radha Gruul Spellbreaker Halana and Alena, Partners Impromptu Raid Invigorating Hot Spring Itzquinth, Firstborn of Gishath Killer Instinct Klauth, Unrivaled Ancient Kogla and Yidaro Last Night Together Minsc & Boo, Timeless Heroes Owen Grady, Raptor Trainer Pako, Arcane Retriever Palani's Hatcher Primal Visitation Raging Kavu Rampaging Geoderm Raph & Mikey, Troublemakers Ravager Wurm Regisaur Alpha Revel of the Fallen God Rhino, Barreling Brute Rhythm of the Wild Rip-Clan Crasher Rubblebelt Rioters Ruby, Daring Tracker Rydia, Summoner of Mist Samut, Tyrant Smasher Samut, Vizier of Naktamun Samut, Voice of Dissent Sarkhan Vol Stampede Surfer Toph, Hardheaded Teacher Wildfire Wickerfolk Wolverine, Fierce Fighter Xecau, Predation's Shadow Xenagos, God of Revels Xenagos, the Reveler Yarus, Roar of the Old Gods Zhur-Taa Goblin

Active openers also earn points toward free drops
It is the slowest major format in the game, taking anywhere from thirty minutes to a few hours to complete games