Scholar: Feo Ul version of the Spectral Statice mount, or princess carried by the larger King Feo Ul.


Astro: Sitting atop a floating black hole with similar shape to Ozma mount, or a mini floating galaxy where you lay curled up in an ball inside the middle.


Whm: Some sort of Sin Eater would be cool, preferably Forgiven Obscenity.


And for Sage i'm not really sure I can think of a good one, maybe some sort of futuristic ambulance that transform into a airship when in flight would be funny.
Or maybe using your weapons as floating platforms to carry you around.