However, before we name contenders, let's establish the key criteria that shape this iconic debate
The set is also confirmed to have cards from every mainline numbered entry, so unfortunately we shouldnt expect cards from things like Tactics, Type-0, and certainly not Kingdom Hearts

Aboleth Spawn Abomination Abomination of Gudul Abomination of Llanowar Abyssal Gatekeeper Abyssal Gorestalker Abyssal Horror Abyssal Nocturnus Advanced Stitchwing Ahriman Ancient Cellarspawn Appendage Amalgam Arcbound Fiend Armaggon, Future Shark Arvinox, the Mind Flail Atraxa, Praetors' Voice Awoken Horror Balefire Liege Bedlam Reveler Blistergrub Bloodcurdler Boneshard Slasher Brainstealer Dragon Bruna, the Fading Light Cabal Therapist Canker Abomination Captain N'ghathrod Carnival Carnivore Carrion Locust Cateran Brute Cateran Enforcer Cateran Overlord Cateran Slaver Chained Throatseeker Chasm Skulker Childhood Horror Chittering Host Chupacabra Echo Clammy Prowler Cleaver Skaab Comet Crawler Conduit of Storms Consuming Aberration Core Prowler Corrupted Harvester Cosmic Horror Crawling Chorus Creakwood Liege Creeping Inn Cruel Witness Crypt Lurker Cryptborn Horror Culvert Ambusher Cursed Monstrosity Dark Hatchling Dauthi Horror Deathbonnet Hulk Deathbringer Liege Defiler of Flesh Delraich Demolisher Spawn Despoiler of Souls Devouring Strossus Devouring Sugarmaw Dinrova Horror Docent of Perfection Doom Weaver Douser of Lights Dread Osseosaur Dread Reaper Dread Slag Dread Slaver

They also have the lowest values among set EVs
While a Control deck in Standard might be able to build itself to beat a particular metagame, that's usually not a realistic proposition for Modern, especially in long tournaments where you're guaranteed to play against random stuff