BIG PICTURE
(skip to "ACTUAL QUESTION" below if you just want the question)
I'm playing a ritualist (aspect from Signs of the Moon - SotM) bone shadow ithaeur. Needless to say, I'm very focused on rituals and sometimes I develop my own rites. Also, I have the "The wisdom of patience" wisdom gift (SotM, p67) and when roleplaying I favor patience over immediate action. Those are some necessary background infos.
I've performed the "Rite of slaying the truth" (Tribes of the Moon - TotM, p74) on a human who knew too much about something that was crucial for our enemies, but otherwise he was "kind of innocent" (won't get too deep into any of that). I got a dramatic failure on that rite and he lost all his memories. The book describes it as if the insect I used was too strong and killed all of the target's spirit-memories.
I want to revert that for two reasons:
First, it isn't like my character to leave that "kind of innocent" human like a walking brick. He should have lost only the intended memory and my character blames himself for what happened and will try his best to make things right.
Second, I want to use this whole situation (failing and then solving it) to fulfill the "Words of power" milestone gift's (TotM, p69) requisite of failing at something important, learning from that mistake and correcting it. As wise and patient as my character is, he wanted to get ready to perform the ritual by learning medicine (the rite has some mods based on that skill), but then he decided to rush it and, unprepared, performed it sooner than planned - storywise he thinks that's why he failed so hard.
ACTUAL QUESTION
Knowing that the rite of slaying the truth is about killing a spirit-memory, thus knowing that memories have spirits related to them, my character wants to undo the target's memory loss using other living spirit-memories. But how can he do that?
I've considered developing a new rite that transfers a spirit-memory from one person to the other. That way I could give that human my own memories about him (except the memory I originally wanted erased, obviously). Alternatively, I could make a small hidden scar fetish on the target (eg: his scalp) using said spirit-memory or even a consumable fetish (eg: something that could be eaten/drunk), therefore giving me more control over possible negative effects in case I fail (eg: if I fail at transferring my memories via rite, I could make myself amnesiac while the target gets all my memories; if it's consumable, I could leave a note to myself before performing the rite telling me to consume it if I'm feeling mindblank, thus getting my memories back).
That's all too beautiful, except that it revolves around using a spirit-memory that isn't the target's. That means the memories are from a third person, so the target wouldn't really get his memories back, but instead the memories someone has about him. It simply won't work well.
To get a first person solution, I've considered travelling to the Realm of Death (don't really know how it's called in english) to see if I can find the dead spirit-memory's phantom and somehow get the memory to myself and then use one of the solutions above. But I don't know if that's even possible, not even if dead spirits can become phantoms. I don't know how the Realm of Death works, but I've been there once during my bone shadow initiation and was taught that I shouldn't mess with the phantoms there, just let them "rest in peace" (or whatever that means for them). Maybe that won't work either and dead stuff is out of the scope.
So, what can I do to revert, to an extent, that nasty dramatic failure effect? How to reconstruct some of his memories so that at least he recovers his identity and personality?