Animae Durations

I couldn't find the answer on the boards or in the books, so I'm hoping someone can help me here.

For the Major Inner Mystery: Animae from Merinita (HoH:MC) is it possible to:

a.) Create permanent faeries using Creo?
b.) Create permanent faeries using Muto?

Also, is it possible to turn a creature with Might, i.e. a Griffon, into a Faerie using Animae?

Finally, is there a size limit to what can be effected? For example, could a Maga with appropriate an Magical Focus and Muto Terram scores turn a Castle into a Faerie?

One idea was to make a sentient Faerie castle using MuTe(He) to make it self-aware and able to manipulate itself and speak to people within it (slaming doors, dropping gargoyles etc.)

This would be helpful as I'm trying to design a new Merinita nemesis for a saga, and need to know how far her powers can be streached.

Thanks in advance.

I suppose faeries might be created with a Momentary Creo [Form] ritual.

For Muto [Form] I'd go with "Until" the faeries have Might so they're immune to Warping and while they will be destroyed if their Until condition is fulfilled, this isn't qualitatively different from a Sovereign Ward...

I'm not sure that faeries qualify as a natural thing, the creo animal rules allow magi to create natural magical creatures so this doesn't seem to be too unreasonable.

I've no books near me now but I'd wager that the text might address this issue by specifying pretty clearly what the mystery does.

They'll also be destroyed when the caster enters twilight.

The option I've discussed before is enchanting the animae magic effect into a device as a continuous effect.

The guidelines for creating elementals (RoP: M, pg 133) would seem to vindicate me, but without any unique insights into the metaphysics of Animae Magic it's probably a matter best left to the discretion of individual SGs.

I've toyed with some of the other Merinita guidelines, most notably in the form of Recurring spells and the "Might" duration, but neither seems quite satisfactory. Enchanted devices seem reasonable, however. More intriguingly, it might even be possible to enchant a Personal range Animae effect into an otherwise inanimate object...