Observations:
[ul]This snake is the same kami that was in Chapter 1: https://mangadex.org/chapter/726012/39 . With this chapter, it is revealed that both of the kami on the Volume 1 cover are the same (the faceless emperor form and the giant snake).
Kuina, the girl from this chapter, was the bird in Chapter 3.5 that was delivering the rope back to An'inseki after it was damaged in Chapter 1: https://mangadex.org/chapter/787940/2
Kisara, the girl's sister with a broken leg, was the one that Kippuuson originally called for but she was out: https://mangadex.org/chapter/787940/1
Sahiri, the spider's miko was also first mentioned in 3.5 when Kippuuson told Kuina to send his regards to Sahiri: https://mangadex.org/chapter/787940/5
We also see the aged human form of Kippuuson and Sahiri. Note that she is still wearing the sun around her neck in the picture: https://mangadex.org/chapter/787940/5 . Also, it seems like he his power has weakened like the monk mentioned; he is no longer able to travel anywhere he wants in time + space by looping his own body and needs to rely on the treasure. Even then, the destination seems to be fairly random (or at least decided by "fate") He also seems to have aged significantly when compared to his human form shown in this chapter.[/ul]