If a player is able to fill their graveyard through either self-mill or discarding effects, this can potentially be used to subvert the high mana costs of impactful creatures
The Planar Chaos design team wanted to focus on color switching and thus also shied away from using old mechanics in new ways (well, other than using them in colors they hadn't been used in before)
Anathemancer Archfiend of Sorrows Artificer's Dragon Ashnod's Harvester Brackwater Elemental Canoptek Tomb Sentinel Chronomancer Cityscape Leveler Combat Courier Corpse Connoisseur Dregscape Sliver Dregscape Zombie Etherium Abomination Extractor Demon Fatestitcher Fire-Field Ogre First-Sphere Gargantua Ghost Ark Grixis Grixis Slavedriver Heavyweight Demolisher Hell's Thunder Hellspark Elemental Hexmark Destroyer Kathari Bomber Kathari Screecher Kederekt Leviathan Lokhust Heavy Destroyer Mask of the Jadecrafter Meticulous Excavation Mishra's Juggernaut Mishra's Research Desk Mishra, Tamer of Mak Fawa Molten Gatekeeper Perennial Behemoth Phyrexian Dragon Engine Platoon Dispenser Priest of Fell Rites Reconstructed Thopter Rotting Rats Royal Warden Salvation Colossus Scourge Devil Scrapwork Cohort Scrapwork Mutt Scrapwork Rager Sedraxis Specter Sedris, the Traitor King Shambling Remains Simian Simulacrum Skorpekh Lord Solemn Doomguide Terisian Mindbreaker Terror Ballista Tocasia's Onulet Tomb Blade Tri-Sentinel, Act of Vengeance Triarch Praetorian Undead Leotau Viscera Dragger Vithian Stinger Yotian Frontliner
Eye The Jeskai (blue-red-white), being about cunning, is the eye of the dragon
Some sets stand out because they pack in a ton of zombies, especially the ones that pull in multiple planes of the Multiverse
