I went as mainstream as possible ('selling out'? ) with this one.
The following for these two is huge. How will this do here and on Twitter?
Whatever is fine.

Played a lot of Mario games growing up, watched the series, and the movie.
Recently, a little Mario Party and Smash Bros due to the housemates.
Watched a playthrough of Sonic Adventure and some animation long ago. Hope to see the movie.

Got background reference from a screenshot, then changed it up a bit.
Backpack for Sonic to make it unique(?)
I looked to Mario and Sonic at the Olympics and Smash Bros. Ultimate for design ideas.

Rights to Nintendo and Sega.

https://www.deviantart.com/jettmanas/art/Mario-and-Sonic-877921773