A Nanoha-based RPG

I'm rewatching the movies (again) and I've recently began looking at forum role playing again. I want to play within the Nanoha realm, as it's exciting and has a ton of potential for just imaginative creativity. The influence of magic, realms, spells, IMDs, there's so much to create!

I'm pretty open on game system choices. My typical go-to is Big Eyes Small Mouth, but perhaps there is a better system to define the spells, and Intelligent Magical Devices? And it would have to work well for a play by post setting, so I'm not sure how well that will work, as the realm of Nanoha is combat intensive.

And while playing the canon cast would be fun, I think that creating origins characters would be more rewarding and liberating.

So, my question is this: does this have any interest? (And I'll probably repost in r/RPG as well for more system opinions.)