Well, when we learned that Sonic was likely going to end up in a fighting match with Knuckles for Sonic Channel's next Fantasy Artwork piece, we certainly weren't expecting this! November 2023's Sonic Calendar art has been revealed, and shows a gallant 'fighting king' Knuckles in the ring with... a clown Sonic.
Don't be so surprised - this kind of setup is all part of the Sonic Channel's "Isekai Ohgiri" art series, which features familiar Sonic characters in unfamiliar (and even surprising) scenarios. The Sonic Channel page for this artwork (where you can also download a PDF of the November 2023 calendar) outlines the situation as follows below (machine translated):
This time, the defender with the proof of victory, Knuckles, the fighting king, takes on the sonic clown, the challenger Sonic! The outcome of the dream match where power and speed collide is...! ?
Fans are encouraged to share their own narration of what is happening between Sonic & Knuckles on social media, and Sonic Channel says it will highlight their favourites ones. To kick things off, the Sonic Channel page comes with an example story that can help inspire your own one. But there's something else too...
Further down the page is a parallel storyline that seems to tie all of the monthly Fantasy Artwork pieces together. Everything from this scenario, to Detective Cream, Blaze and Silver's elemental service, Superhero Vector and more all seem to centre on one thing - the Phantom Ruby. Turns out all of these crazy scenarios are in fact alternate realities that are being summoned in order to generate power for Dr. Eggman's latest creation.
... I'll be honest, it's an absolutely CRAZY bit of Lore that you'd easily miss if you don't visit Sonic Channel and can't read Japanese, but it's quite inspired all the same. It'd be even crazier if this all tied into Sonic Dream Team somehow...