You've elongated the history, instead of making it more concise, and added elements that cannot be approved, such as this strange gel and pillar.
Part of what you must understand is that medical science at this stage of the game is extreme. Lost all your limbs? They'll grow you new ones. Suffered a fatal accident? ST'd into a new body. Cut along your arm? In a Yamataian body, it heals up itself within an hour.
Yamataian citizens have a very strong element of immortality when it comes to their existence. You seem to acknowledge that, having to create strange plot points just to damage the character enough to get her in a Neko body.
Yet, it still wouldn't work — she'd just get put back into a regular Geshrin body, or, with the timing you have, a Yamataian body.
You're going to great lengths to make her a Nekovalkyrja, and for what? To satisfy your board avatar? It's too much. If you really want her to be a Nekovalkyrja, you should just make her a fresh Neko, or even a Neko that's been alive for a few months.
I appreciate the lengths you're going to, and the determination you have. I feel I'm partially to blame for this, somehow. But you should just make her a regular Neko, without a Yamataian past, and move on.