As one commenter, although I do feel it fits more as Stage 5 Boss Theme, wow, this is amazing! Wouldn't honestly mind if it was the actual Stage 5 Boss Theme instead of Clownpiece fight we have since I'm not the biggest fan of it. Not to say it's bad, but this...oh wow!
After listening through all of the versions of this song in the styles of the different games, I can say that this one is my favorite. The splitting of the one note into three starting at 2:23 was that cherry on top for me.
Another dude turn into a girl. Same goes for tenmu. Mitama is Sugawara no Michizane , a famous scholar and poet, one of three great vengeful spirits of japan. Since he’s a divine spirit, he can alter forms. Google for more for why he is thunder god or tenjin.