That sounds like a fantastic idea Enso, even though it is basically impossible to "tank damage" from a Colossi when most of them are 5 stories tall!
Raea probably would be the best Horse-Rider, and the most acrobatic, not at all stereotyping them. I'd be happy to fill the role of the archer in the group!
As soon as I can speak to Raea I'll start setting up the OOC.