@tc
I like your analysis on many of the themes, but some my opinions are slightly different. By actually playing the themes (on piano) in addition to listening to them for background melodies and such, some themes seem more complex than they seem and others, simpler than I would have thought. Though I don't think I can totally express my opinions for the themes as intricate as you do.
I'm going an analysis of one of my favourite themes here. Pardon if some parts are inaccurate, I'm doing the analysis from memory of the themes by not actually listening to them.
The Ancient Venerable Battlefield - Suwa Foughten Field
This theme, thought at first didn't appeal to me much, already signified to me a special vibe to it at first hearing. It has a grand opening intro, coupled with wind sound effects and syncopated drumbeats. A short 4-bar phrase, then an even more grand repetition of this phrase, which connects into one high note sweeping down into the second part. This second part (broken octaves) doesn't start at the bar, but simultaneously while the sweeping section is about to end. It's like a tunnel funneling into the more simple but mysterious section. I always imagine the beginning signifying the presence of Kanako, a power to reckon with, an extrememly fitting boss aura. The broken octaves part is complemented by the piano, which is supposedly musically more important (since the broken octaves is repeating). This sudden more tranquil feeling brings about the landscape, the scenario, where you meet Kanako. The wind blowing across with leaves scattering around, the mighty onbashira in the vicinity, the 'Ancient Venerable Battlefield'. It then proceeds to a very recognisable part, in which, I don't really know how to describe. But the 'dah-dah, da, dah, duuuh-dah' rhythm is surely memorable to me, and it gives this very imposing feeling to the listener. It's like Kanako charging up her power for some attack. In fact, every time I hear this I'm reminded of Kanako starting the pattern of her Mountain of Faith spellcard, in which the rings expand out before flying off. Every 2 bars of this rhythm, a new outer ring (of Mountain of Faith) appears, bigger than the last, adding to the multicoloured destruction about to expand and disintegrate. This then leads to the next part, which, though it only played once in the whole theme (ignoring repeats), is what I consider the main part:
This part is signified by ZUNtrumpets. A flowing melody, in minor key, and suddenly changes to 3/4 time. It's the embodiment of the presence of Kanako, using her powers to launch her main assault. To me, this is the main part of Kanako's theme. The previous part, the set-up, and the introduction of the environment, is for this main part to come in. To make it more obvious, the melody is changed to 3/4 time, but suprisingly not awkwardly. At the end of this main part comes the broken octaves again, albeit with a more surging bass this time, as for this time it is not introducing the surroundings to us. It lasts twice as long as the first time, with the chord changing the second time. After that, it links to the recognisable part again, and again it is different from the first time. There is a more echo-like feeling to the instrumentation, the sudden flash of the eye Kanako gives you for lasting so long in this battle. This time, the notes surge even more, higher at the end, but instead, it all suddenly disappears:
Now this next part, more quiet, and yet melodic but unfitting of what has happened so far, is more like a flashback to Kanako's past. In fact, what fits this part so well is this youtube video I watched of the EWI version of this song. It is no longer Kanako of the present, but the Kanako of the past, and what she did to triumph Suwako. In between the phrases are high notes decending down, and rising up again, showing the all-knowing brain of the Goddess. The second time this part repeats, it gives a even more 'nostalgic' feeling, with the faster bass notes and added rhythmic 'clap' every 2nd and 4th beat. It then surges back, into the mood we had in the beginning, jolting back to the present. This next part is signified by ZUNtrumpets again, but its elegance in the melody is there. Kanako is using what she had learned to counter her faults. This is signified by the bass part, which actually is still continuing from the previous part, though it's not obvious because of the ZUNtrumpets overpowering them. But overpowering them is what they should do, while the continuing bass part from the 'past' is going on. It then surges high and mighty into a finale-like theme, with strong echo'd drumbeats to back up. However, instead of finishing, it dwindles back into the broken octaves, quiter than the second time, more mysterious than the first time (perhaps because it's in a different key). The wind effects from the introduction are back. It's like the battle is over, and Kanako no longer lingers around the surroundings, but openly shows her true non-imposing self. At the end of this part, it loops back to the 'recognisable' part, but usually I end here if I'm playing the piano version of this piece (which I can't do justice), because that last chord, though not a perfect cadence to end the theme, brings about a peaceful vibe to it, after all the trouble in the past which has brought this Goddess to what she is now, and today.
My opinion relates more to the actual instrumentation rather than linking the piece to the character, but usually my imagination when a theme is playing is when the character is actually moving around doing what it should and would instead of just standing there. Refering to this, Kanako moves a lot, but in the end, she is in reality a very knowledgeable person who knows who to confront and who to trust.