Waste of time, but I'll play.
Loose plot points:
Takes place after SF3
World Warriors new and old (in game and out) are seeking to kill Akuma for their own reasons. For most it's about the Satsui no Hado.
Shadowloo/Illuminati (former and present) are being hunted and killed by an unknown group (Spoilers, it's Q). Vega barely escaped death and Bison was saved a mystery character. Cammy and Rose are actively being searched.
Main Characters: 2
Sakura (Japan)- Age 21-25, Ryu refused to train her. If he did, I'm retconning it, her shoto style will be completely different. Others have taken her in though, notably Guy, Cody, and Dee Jay. Gameplay wise she will be the Hurricane Kick/Wind character, many moves will be borrowed from Rashid including Hadokens fused with wind, running, wall bouncing and the nimble/aggressive gameplay. Guy and Cody's training will definitely be noticeable. Sakura is one of the people searching for Akuma.
Rao (South Africa)- Age 21-25, a male doll intended to be Bison's new body. Like Vega he escaped death and is on the run from both Q's agent and Bison. He is slowly recovering his past memories. Basically I'm replacing Nash, just not a fan of the resurrection. His story was told in Alpha, let's move on. Nash's moveset can breathe life into a new character for SF. I have an Indian friend from South Africa, thought this is a cool way to represent that community.
Veteran cast: 8
Ryu, Ken, Chun-Li, Cammy, Zangief, Dhalsim: Mostly fine, would change up some of their looks. Ken is a 30-35 year old man with a family, his fucking hair is ridiculous.
U. Mika and Birdie: OMG, a heel turned Mika? Lanshing at fans, Mika reveals she is actually an Argentinian Luchador! She grew tired of appeasing the Japanese audience and will now show them what "real" wrestling is! Ultra Mika and "The Black Sun" Nadeshiko is a heel stable, something you would see in NJPW or WWE. Birdie is in the group with matching pro wrestling gear. Since wrestling is an act he is constantly confused what is or isn't real (is this fight with Bison apart of the show?). Birdie and Mika would show up in each others supers, just like Nadeshiko. Overall, it's a comedy relief group for the game.
Younger Cast (Age 20-28): 6
Meissa (France)- "The Superstar", action director, stuntwoman, actress, that sort of archetype. Has an animal style Kung Fu, flashy and cool looking. I liked the idea of Ono making an Arab fighter, but did it have to be a SF version of Shaheen? Let's go another direction. She has ice abilities (goodbye Eisbahn) and unoriginal move names like Cold Star and Solar Flash. Superstar/Galaxy themed.
Karin (Japan)- It's Karin...
Sean (Brazil)- Replace Laura, keep the moves. Shoto grappler sounds cool anyway, tailor some of the moves accordingly. The lighting theme can also be tied with Denjin. I'd also keep him away from being Ken's student, he made it just like Sakura. Stupidly seeking Akuma.
Unknown (Israel)- A while back I read up on the Lost Tribes of Israel. Instead of going the Aztec route with Necalli, I'd like to go down this one. A terrifying desert wanderer who seeks souls and feeds off the dead. Tall, slender, probably African decent. Seeks to siphon Akuma's soul.
Makoto (Japan)- "The Shark" of Japan, older Makoto is now fights in the octagon. This girl will have some muscle, her look will be different from SF3
Isaac (Somewhere Pacific)- I like the idea of Akuma having his own students like Gouken. If things soured it's possible they hid to avoid Akuma's wrath. Isaac is a product of one of those students. He would have a mean projectile game (something that's missing), and powerful moveset. He is one step away from the Satsui no Hado but isn't sure if it's the right path. He obviously seeks Akuma for answers.
Boss characters: 4 Vega, Bison, Juri and Q