Updating through Foundations. I've also relented and re-added the Doctor Who cards I omitted before because finding appropriate replacements for some of the removed cards is proving too difficult, so this list should now match the original exactly.

Main:
+Mad Ratter, Nurturing Pixie, Shepherd of the Clouds, Requisition Raid, Getaway Glamer, Harrier Strix, Canyon Crab, Slickshot Lockpicker, Phantom Interference, Forsaken Miner, Priest of the Blood Rite, Lively Dirge, Voldaren Epicure, Scrapwork Mutt, Oliphaunt, Spinewoods Paladin, Predator's Howl, Intimidation Campaign, Honest Rutstein, Outlaw Medic, Highway Robbery, Dance of the Tumbleweeds, Indebted Spirit, Glyph Elemental, Aerie Auxiliary, Witch Enchanter, Mandibular Kite, Serum Visionary, Brainstorm, Brainsurge, Sink into Stupor, Marionette Apprentice, Accursed Marauder, Wurmcoil Larva, Eviscerator's Insight, Fell the Profane, Reckless Pyrosurfer, Skittering Precursor, Pinnacle Monk, Skoa, Embermage, Temur Battle Rage, Ghostfire Slice, Fanged Flames, Kumano Faces Kakkazan, Rubblebelt Maverick, Eldrazi Repurposer, Territory Culler, Collective Resistance, Malevolent Rumble, Nyxborn Hydra, Eldrazi Ravager, Breaker of Creation, Make Your Own Luck, Pyretic Rebirth, Writhing Chrysalis, Tranquil Landscape, Sheltering Landscape, Bountiful Landscape, Perilous Landscape, Twisted Landscape, Deceptive Landscape, Shattered Landscape, Foreboding Landscape, Seething Landscape, Contaminated Landscape, Tax Collector, Shrike Force, Grey Knight Paragon, Plumecreed Escort, Splash Lasher, Eddymurk Crab, Thought-Stalker Warlock, Fell, Diresight, Coruscation Mage, Cache Grab, Short Bow, Improbable Alliance, Miner's Guidewing, Militia Bugler, Lionheart Glimmer, Dewdrop Cure, Essence Reliquary, Surgical Suite // Hospital Room, Floodpits Drowner, Unnerving Grasp, Meat Locker // Drowned Diner, Popular Egotist, Testament Bearer, Huskburster Swarm, Live or Die, Norin, Swift Survivalist, Brazen Collector, Irreverent Gremlin, Sontaran General, Start the TARDIS, Iraxxa, Empress of Mars, Sonic Screwdriver, Ominous Cemetery, Razorkin Hordecaller, Painter's Studio // Defaced Gallery, Hunter's Talent, Sawblade Skinripper, Shroudstomper, Arabella, Abandoned Doll, Goblin Trenches, Sandstone Oracle, Talisman of Curiosity, Sun-Blessed Healer, Helpful Hunter, Guarded Heir, Sheltered by Ghosts, Mischievous Mystic, Cynette, Jelly Drover, Faebloom Trick, Unable to Scream, Vampire Gourmand, Dragon Trainer, Goblin Surprise, Origin of the Hidden Ones, Sutina, Speaker of the Tajuru, Hivespine Wolverine, Atraxi Warden, Craig Boone, Novac Guard, Gary Clone, Butch DeLoria, Tunnel Snake, Young Deathclaws

-Swashbuckler Extraordinaire, Faerie Guidemother, Custodi Squire, Sunder the Gateway, Against All Odds, Spectral Sailor, Azure Mage, Icewrought Sentry, Neutralize, Skinrender, Gray Merchant of Asphodel, Phyrexian Reclamation, Fireblade Charger, Goblin Instigator, Crimson Mage, Goblin Heelcutter, Light Up the Stage, Llanowar Visionary, Arborback Stomper, Briarhorn, Beast Attack, Vohar, Vodalian Desecrator, Baloth Null, Serrated Arrows, Skymarcher Aspirant, Tireless Provisioner, Doomed Traveler, Dawnbringer Cleric, Relief Captain, Mentor of the Meek, Gryff's Boon, Brineborn Cutthroat, Sea Gate Oracle, Gitaxian Probe, Thirst for Discovery, Capsize, Zulaport Cutthroat, Guildsworn Prowler, Graveblade Marauder, Village Rites, Poison the Cup, Grishnákh, Brash Instigator, Seismic Wave, Red Dragon, Twinferno, Stoke the Flames, Flame Slash, Experiment One, Wolfir Avenger, Snapping Sailback, Grapple with the Past, Wilderness Reclamation, Sphinx of the Guildpact, Ulamog's Crusher, Frilled Mystic, Terminate, Goblin Anarchomancer, Citadel Gate, Thriving Heath, Sea Gate, Thriving Isle, Black Dragon Gate, Thriving Moor, Cliffgate, Thriving Bluff, Manor Gate, Thriving Grove, Norn's Inquisitor, Aerial Responder, Herald of the Host, Zephyr Sentinel, Micromancer, Sailors' Bane, Night Clubber, Bloodchief's Thirst, Read the Bones, Guttersnipe, Commune with the Gods, Dire Mimic, Saheeli, Sublime Artificer, Battlefield Raptor, Danitha Capashen, Paragon, Shepherd of the Cosmos, Éowyn, Lady of Rohan, Felidar Guardian, Kirtar's Wrath, Merfolk Trickster, Callous Dismissal, Treasure Cruise, Sling-Gang Lieutenant, Sanguinary Priest, Gurmag Angler, Extinguish All Hope, Frantic Scapegoat, Battle Cry Goblin, Goblin Cratermaker, Phoenix Chick, Favorable Winds, Sprouting Goblin, Worn Powerstone, Forsaken Crossroads, Éomer of the Riddermark, Inspired Tinkering, Up The Beanstalk, Stormclaw Rager, Angel of Despair, Koll, the Forgemaster, Akiri, Fearless Voyager, Walking Skyscraper, Phyrexian Missionary, Spirited Companion, Fairgrounds Warden, Faith's Fetters, Wing Splicer, Windrider Wizard, Stern Scolding, Legion Vanguard, Pugnacious Pugilist, Incinerate, You See a Pair of Goblins, Slice and Dice, Acidic Slime, Sentinel of the Eternal Watch, Honored Crop-Captain, Knight of Dawn's Light, Knight of Dusk's Shadow, Worm Harvest

character limit, cont. in reply

Following the MKM update here: https://cubecobra.com/cube/blog/blogpost/a145af37-aeb6-4364-8b05-f917d5376384
I'll be updating this list as I get cards to replace what I already have.



+Frantic Scapegoat, Aftermath Analyst, Goreclaw, Terror of Qal Sisma, Surrak, the Hunt Caller, Kiora, Behemoth Beckoner, Scuttling Sentinel, Escape Tunnel, Undercity Sewers, Lush Portico, Meticulous Archive, Underground Mortuary

-Goldhound, Jade Mage, Kraul Harpooner, Halana, Kessig Ranger, Troyan, Gutsy Explorer, Fleetfeather Cockatrice, Mana Confluence, Temple of Deceit, Temple of Plenty, Temple of Enlightenment, Nurturing Peatland

As of the big 2023 update to MatEffect's cube, I've decided to take some changes in a different direction. Notably, I really dislike the Doctor Who set for personal reasons (it doesn't fit the game well imo), so I'm not including any of those cards. That said, some of the changes in that update seem beneficial given the direction of the cube--particularly removing Mad Ratter in favor of some other red creature in that slot. I'm opting to slot in Swashbuckler Extraordinaire for its aggressive capabilities, and the extra treasure to boot. I think it will be cheap enough to be worth a slot in aggressive red decks, and flexible enough to be worth the slot late-game in bigger decks eg. red/green, and a free treasure is nice regardless of whatever else it might achieve in the game.