Oooooh this is fun!
I would like to think with the two smaller characters being off balance in nature has lead them to learn a spinning motion way o moving that optomises their heavy side swining to move their weight.
Heck you already made one of each of their legs a fine top, and because the have martial air to their design, i can really imagine them doing 360 swing haymakers and such.
It would be if in the separate forms they also had semi distinct fighting styles that work well when fused.
So like if Sable did Capoeira, which works well with their cocky smile, and Ivory specialized in using their opponent's weight against them like Judo or Bagua which works well with their more withdrawn countenance.
figuring out how to balance the two styles could be a really solid character arch, and possibly good fodder for physical comedy, but in any case, i really like it, and I appreciate the monochrome vibes of blue.
Thank you for making this.