I don't personally rp an Au-Ra but a lot of my friends do. Honestly, the bulk of them treat the dark scaled ones like miqo'te - as in tribal and somewhat feral. Considering that there is lore stating that a clan of dark scaled Au-Ra were killed by some Ishgardian knights you could easily say your character is seeking revenge. Or maybe they want to team up with the Little Ala Mhigans to help take down Garlamald and learn the ways of the monk.
There's a lot of places you could go with it but it's all for not if you don't have the right people to rp with. Look around, try to meet some new faces and see if that doesn't help spice up your rp life.
If you're worried its because you're playing a girl character (which I totally get. I'm a female player who loves her boy characters) then think about what would change if you made her male. If those changes are positive maybe you should make a male Au-Ra.
There's a lot of places you could go with it but it's all for not if you don't have the right people to rp with. Look around, try to meet some new faces and see if that doesn't help spice up your rp life.
If you're worried its because you're playing a girl character (which I totally get. I'm a female player who loves her boy characters) then think about what would change if you made her male. If those changes are positive maybe you should make a male Au-Ra.