As you can see, there's two South Park major console video games, and they both have themes; Stick of Truth is based on the Fantasy theme, and FBW is based on Superheroes theme. This next one, will be based on the Mystical theme. In other words, this one parodies and centers on religion as well as Greek and Roman mythology.
For starters, the whole crew of the Super Best Friends has a major role this episode. Even Seaman is not left out; he allies with Stan.
Kyle, along with the rest of the Broflovskis, since they're Jewish, become allies with the Super Best Friend Moses. Jesus, since he's technically Jewish too, offers them support. The Jewish society forms and they all form one fort, and they have frequent meetings in the Hall of the Super Best Friends. Kyle and his crew is antagonized by Cartman and most guys of the crew are bosses.
On the Greek mythology side, we have several of the kids dress up as the Olympians, and are the main allies for combat. The Olympians are:
Token is Zeus
Stan is Poseidon (which explains his alliance with Seaman)
Kenny is Hades (instead of Hermes, as Hades makes more sense since he's the God of the Dead)
Cartman is Ares (which is by far the most accurate)
Scott Malkinson is Hermes
Wendy is Amphitrite (Poseidon's significant other, and in actual Greek mythology, she's the sole non-Olympian in the squad)
Clyde is Apollo
Heidi is Artemis
Nichole is Hera (Zeus's significant other)
Francis is Ceres
Kevin Stoley is Vulcan
Annie is Aphrodite, and finally
Nelly is Hestia
The Olympian meetings are held at Token's mansion
On the Christian-Satanist side, we have the other guys, most of them which defend the Church:
Red is a Satanist (the Dark Angel), and fights to avenge Satan, ultimately becoming ManBearPig's foe
Timmy is a Catholic Pope (and is not playable)
Priest Maxi is also not playable, but does give out missions
The Choir Boys are: Butters, Craig, Tweek and Bradley. They require missions to be completed to be unlocked and fight on the Olympians' side.
Jimmy is the Friar, he'd also require missions to be completed to be unlocked and fight on the Olympians' side
Bebe is Medusa, and is one of the bosses early in the game, but once defeated she can become an ally
Medusa Bebe's companions: Millie, Kelly Gardner, Jenny Simons, Jessie, Kal and Powder all fight on your side in the final mission. Jessie and Kal are also featured in a DLC
Mr. Garrison is not playable, but gives out quests
The other SBFs (Joseph Smith, Krishna, Muhammad (who is censored), Buddha and Lao Tse) all fight on Kyle's side, but Smith and Buddha eventually defend the church. Smith is featured in a DLC
The bosses are:
The old Superheroes, Bebe, the 6th graders, Gerald (there's also several references to SkankHunt42), Randy and Towelie (antagonized by Stan, Towelie can become an ally later on), Mr. Slave, Vampire Kids, Sheila, Ike (twice, the second time he's on hormones), the police force (antagonized by Token), Heather Swanson, ManBearPig (Red is unlocked as an ally), Cyclopes (throughout the game), Moses and finally Kyle Broflovski and his minions. Eventually conflict between the Christian-Olympians and the Jews is resolved by Token and Jesus.
The New Kid can choose what God (or Goddess) they want to be, provided it's not one taken by the other kids, for example I'd choose Tartarus (God of the Deep Abyss), and the New Kid would be known as Tartarus for the whole story. The New Kid also has basic speaking lines, mostly said throughout combat, but not a very advanced vocabulary.
The main social media parody platform, was Facebook for Stick of Truth, and Coonstagram for FBW. This time, it will be a parody of Snapchat, and many people will be able to be added friends on the app, including the entire squad of the Olympians (and Wendy).
About 50% of the side quests in the game have something to do with religion. The religious ones are mostly issued by Seaman, Bebe and Priest Maxi. The non religious ones are mostly issued by PC Principal, Strong Woman and Mr. Garrison, for example defeating Mr. Slave and Heather Swanson, who turns into a cyclops mid-combat, but reverts after being defeated.
As for the DLCs which I mentioned, they involve stuff that parodies episodes and scenes from the past, similar to how From Dusk Till Casa Bonita did:
The Kal-Jessie DLC features Spoiled Stupid Whore (which is pretty ironic) and a freshly restored South Park Mall, and they have to take down Wendy's father, who's threatening to destroy the store. Bebe's there to help
Smith's DLC involves defending Mormonism
Other DLCs include helping the girls with a mystery (similar to Stick of Truth but a different plot)
Finally, similarly to the Human Kite and Super Craig in Fractured but Whole, Friar Jimmy and the Choir Boys will require missions to be completed so they can join alliances with the Olympians. This would include defeating Jimmy's nemesis' Nathan, as well as helping Tweek and Craig reconcile (they've been having arguments 24/7 lately; Butters and Bradley can't break it up, but will help the New Kid in completing it).
So there it is, my ideas for a new South Park game. Sorry I made this post so long, but what do you guys think?