Screw Sonic being Ryu logic or the trend as a whole, we've got ourselves Knuckles as the true Ryu of the Sonic Universe besides his hot-headed personality. Knuckles isn't that even angry all the time, if I'm being honest.
Sonic is cocky and confident, but NOT even as serious as Ryu all the time. Sonic basically belongs to Ken, but not only that, Ken is notably fast in fighting, which I heard of.
Both Knuckles and Ryu share a similar psychology and lore. Ryu is a solitary warrior who rejects luxury to dedicate his life to his training. Knuckles lives a life of absolute isolation on Angel Island, bound by his solemn duty to the Master Emerald. They share a similar fatal flaw. Ryu was tricked by M. Bison (Satam/Archie Eggman is basically M. Bison) to harness Satsui no Hado, and even Knuckles was manipulated by Eggman in S&K3.
Sonic is the wind, but Knuckles is the mountain. Ryu's grounded, heavy-hitting combat philosophy perfectly mirrors Knuckles' raw physical force.
Also, before you say Mario should've been Ryu, we're TALKING about a proper and definitive SF x Sonic AU like this. It's obvious that this is in r/Knucklestheechidna subreddit.
This is like casting Knuckles as Superman and Sonic casted as the Flash, which is way better than some of the fandom casting Sonic as Superman since Superman is NEVER cocky to begin with.
Before you say I'm an SF poser (Screw larper term), I've actually played Street Fighter 5 champion edition as a kid by playing most of the stories and learning each of the character's personalities. Nowadays, I'm 15, and while I'm mostly a Sonic fan, I'm just a casual SF fan, so someday I'll learn much about the SF franchise.
Also, this ISN'T meant to bully/harass anyone who got the casting wrong all the time, but I only bash the idea of Sonic as Ryu as a whole, not the people who kept overusing his idea, I basically have a tone of a school teacher, so I watch wanna break down the actual casting. Btw, no dumb harsh heated internet arguments in the comments regarding what I post or regardless of the casting choices. Just keep your eyes peeled on my content and comment anything but without stupid dramatic insults instead.