DISCOVERY PHASE (What are the problems I see?): Why in the damned remains of Tei's victims is THE NECK BONE 0
According to Masisi's Defoko model, which I have because I took it upon myself to never use TDA and rather become not bad at modelling enough to make my own bases, the Master bone at the bottom is bone 0. Then go Center, Groove, upper body, etc.
The bone order is an absolute mess and needs to be worked on before we can do anything with the rigging. Masisi has his(?) neck bone on 5.
It would take an eon for me to fix it, and I have another project in the works, but you should start with correcting the bone order and its links. Check the link in the message, find Defoko's model, and use that as a starting point. Always have properly done models as a reference and copy them. Masisis model is a fair bit simpler, but that makes it easier to follow.
A correct bone order should make things work properly.
I'd actually suggest that if you have troubles finding the correct bones to use the batch name editor to actually, like a madman, swap the english and japanese names around.