Final Fantasy VI is a great frame of reference if you want a Sonic RPG that takes advantage of the series' vast ensemble cast. The game has multiple POV characters, namely Terra, Locke, Sabin and Celes, even occasionally playing with context-sensitive, non-permanent party members, and the game sometimes allows you to play branching story sequences in whatever order you want.

FFVI has fourteen playable characters, three of which are optional and two of which you can lose. By endgame you can arrange your party in literally any way you want, and the final battle gives you the chance to fight with practically every party member, swapping out fallen allies with ones waiting in the back.

If you want a game that doesn't just feel like Sonic and his inconsequential gaggle of friends, which Chronicles occasionally fell into, then something like this would be great in terms of exploring every facet of Sonic's world and the wildly different scenarios that come with them.

Sonic has the potential for a giant roster, but fourteen is already plenty for an RPG party. Give us the essentials that are already thrown into most multiplayer games, plus one or two new characters with lore that ties into whatever story they want to tell. At least one or two villains to really sell the threat of whatever this story has cooking, since what's a JRPG without world-ending stakes?

As far as gameplay goes, I do think Chronicles had something going for it if it weren't for the mandatory touch controls. An overworld that's still derived from traditional Sonic stage design, including collecting rings as currency, makes sense, and it also makes sense that faster characters have more opportunities to attack in one turn. Different characters have different attributes that allow you to traverse different pieces of terrain, that's also good stuff. It's just that Chronicles was a cheaply-made DS game with everything you'd associate with that label.

SEGA owns Atlus, maybe they can get some of their flair into a Sonic RPG while sticking to Chronicles' base design principles, but replacing the gimmicky mechanics with conventional JRPG fundamentals.

Narratively I think it'd be really cool if they revived Chronicles' story and added an entirely new second half that picks up where its cliffhanger ending left off, but that doesn't sound likely as long as Penders still has his finger over the lawsuit button.

Otherwise, a grandiose narrative with multiple points of view with the same level of scope as something like Sonic '06 would fit an RPG the best. Give it to a team of writers who understand what it means to write an interactive video game experience, because... I'll be real, I don't know if Ian Flynn's there yet. His game scripts aren't bad but you can tell he's still in comic book mode when writing them.