A wonderful reference made by  dragonkai! They make the webcomic Twin Dragons, and it's a pleasing read, go give them a look.

I wanted a ref for Muse, but also have general feelings of wanting a sona. I've been the little formidonis kobold for a long time, to the point where people go "oh yeah I recognize the avatar", but at the same time it's nice to ponder new things to be. Isn't that what TF is about?

So have a nice anti-gravity cat. Soft, small, changing people into shapes that make them happy. You can read her chapter over here, and while she herself does not indulge in changing people during that chapter, there are quite a few transformations that happen anyway. Soft bunny girls are a process.

She's the patron of the Mythos faction. Muse is not sure if she's actually a Mew; she's definitely the mythical personification of a talking magical cat companion, who teaches secret lore and empowers more heroic active people to their full potential. And if that represents as a floating cd-powered cat, all the better!
She's tickled by the idea that humans have managed to create a level of mythology beyond religion that tons of people across the world know and understand without necessarily worshiping. Notably in Indulgent TF, no one actively changes into a pokemon without some specific reason; Cotton was changed to match the nature of an existing Lucario plushy, while Muse is an existing archetype that matches closely with a mon.

In any case, she runs a refugee base for mythical creatures that were exploited by others trying to abuse their cool racial powers. Various TMs she's fond of:
* Trial Run - Target tries out a new shape, to see if it's for them. Temporary, and breaks if exposed to combat, but good for testing out and figuring who you want to be.
* Stop That - Target takes petrification damage, solidifying into a substance or inanimate shape that represents their personality. Feeling remorse causes the spell to thaw faster.
* Soothe - Target does not heal damage, but does ignore the negative effects of being damaged such as pain, dizziness, agitation, and so forth.
* Fill Out - Takes target raw materials and makes them into a pre-determined shape, like growing wood out into a wooden bridge. Crafting checks are required for anything fancy, and it's preferable to make simple shapes and let artisans decorate later.