Color variability
I have struggled generally with making recursive dorks that can do so repeatedly, I suspect it is because their power is so linked to answers, support, and overall speed in the format rather than their own inherent power relative to normal cards
Koma, World-Eater The old Koma card was a strong ramp/reanimation spell, and Koma, World-Eater is very interesting as well

Aang, Destined Savior Akoum Battlesinger Akroma's Memorial Alibou, Ancient Witness Alibou, Ancient Witness Anger Arlinn, Embraced by the Moon Badgermole Barbarian Class Blacksmith's Talent Bloodsworn Steward Blur Sliver Centaur Chieftain Cloudshredder Sliver Concordant Crossroads Cyclops of Eternal Fury Dalakos, Crafter of Wonders Deathleaper, Terror Weapon Domri Rade Dragonlord Kolaghan Earthbending Student Ellywick Tumblestrum Emblem of the Warmind Embodiment of Fury Embodiment of Insight Fervor Fires of Yavimaya Firewake Sliver Firion, Wild Rose Warrior Frostcliff Siege Gallia of the Endless Dance Garna, the Bloodflame Ghired, Mirror of the Wilds Gimli's Reckless Might Glissa's Retriever Goblin Chieftain Goblin Warchief Hammer of Purphoros Heart Sliver Hellraiser Goblin Hot Pursuit Immediate Action Immersturm Battlefield (playtest) Invigorating Hot Spring Kamahl, Heart of Krosa Karrthus, Tyrant of Jund Keldon Strike Team Kickoff Celebrations Kragma Warcaller Krang, Utrom Warlord Lavaleaper Lightning Mauler Madrush Cyclops Maelstrom Wanderer Mass Hysteria Maze Rusher Nahiri's Resolve Najeela, the Blade-Blossom Najeela, the Blade-Blossom Najeela, the Blade-Blossom Oni of Wild Places Avatar Order of Sacred Dusk Path of Mettle Phabine, Boss's Confidant Purphoros, Bronze-Blooded Reflex Sliver Rhythm of the Wild Rising of the Day Roar of Resistance Runadi, Behemoth Caller Samut, Tyrant Smasher Samut, Voice of Dissent

Serefin99: And that's my reading comprehension fail of the day
The Mana Base This deck has ugly mana requirements, and for that well have to play a higher number of dual lands and tri-lands