I still think Raven is...quite powerful. If they are in fact Summon Spirits I think Lucy is a pretty good base line. So...if I may make some suggestions? I'll state now that I like fluff...Fluff is a big thing for me and you've got it but...let me get my shears.

I understand she's summoning the Spirits of past people but Summons seem to have one power between them. While she's not over powered...she's got the distinct chance of growing into such very swiftly if she gets to many summons. I would say limit each summon to one power to each. If you feel that limits her down

If they're summons I would also ask that you stick to the Key system of the established world. You could even fluff them to be Skeleton Keys instead of the Silver/Gold and give them a system for really powerful summons and not so powerful summons. It would expand the Summoning World and give possible story arcs later in the future where your character would be a key focus for sure.

The other problem with these games is plots dry up if there isn't at least a little set up for them. I understand that I'm sorta coming in and trying to prune characters but Free Form does run the risk of overpowered characters. I'm also not making these suggestions only after conferring with myself, others have put their heads together on this. I am also not insinuating you or Anime or anyone else would make overpowered characters on purpose. Just...adding my two cents.