Invoking an Ally Spirit, Is this even possible? Options

[Raiki]

Okay, so I'm going to be playing a voodoo magician in an upcoming game. Since my character will be starting quite a while after the official start of the campaign, and with a significant chunk of karma (I'm GMing the fist half) I was planning on making an Ally Spirit. I'm going to be very spirit-focused, so I'm also picking up the Invoking metamagic.

So here are my questions:

1: Can an ally spirit even BE invoked? I've searched the rules for allies, and I've searched the rules for invoking, but all I can find is a blurb on page 57 of SM saying "Note that only bound spirits may be invoked; Watcher spirits cannot be great form."

2: Assuming that an ally CAN be invoked, what would its great form power be? As far as I know, ally spirits don't have a spirit type. A close reading of the powers section of the ally creation section of SM, page 104, would imply that it could be selected from any power a spirit I could summon would have. This seems a bit overpowered, though.

3: On a different but related topic, since my ally spirit would be a possession spirit (Voodoo), would I need to have a vessel prepared for use during the initial binding ritual for the ally spirit as an inhabitation spirit would? Or would the spirit just manifest on the astral realm and function like any other summoned and bound possession spirit?


Any help would be appreciated. Quotes or page numbers would be fantastic, but I understand that this is a grey area that may not have any RAW to back it up, so a Dumpshock consensus would be more than enough for me.



~R~