I've always had a rough idea for the "Greater Sphinx" in my head to counter the Lesser Sphinx. Lesser Sphinx really got the short end of the genetic stick while Greater Sphinxes got better luck. Lessers rely on weapons and armour because their skin is thin and their claws and teeth are essentially useless. Their intelligence definitely helps their survival too.
Since both species derive from gryphons / hyppogryphs I imagined that Greater Sphinx would look a little more similar. There's a lot in this concept I still don't like and need to redraw but a few of the things I had intended are still there. A "hard" muzzle with a beak like tip which is the same colour as their face, Wings (Which the Lesser Sphinx doesn't have unless a rare mutation) and claws that do some easy damage. I'm also liking the feathers on extremities and down the spine. I'm still thinking about what to do with them in their entirety.
We'll see! :)