Help identifying a touhou anime and music remix.

[blast335]

So I was browsing ifunny, when I found this instagram video, does anyone know which touhou anime project this is from and what remix of Septette for dead princess is used?
https://www.instagram.com/p/BJ7LDADABJh-LKNxvwNpN0xjmP3aLtiMlHd0Ec0/

[Rei Scarlette]

Hi, I remembered seeing this quite a while back. I know the song by the name of Pri?re -プリエール- by SOUND HOLIC.

A quick search gives me this link, it's the first I've found with the relevant animation attached to it (and not just the song on its own). https://www.youtube.com/watch?v=lWMBnFoSrWU

I believe it isn't part of an actual anime project (someone do correct me if I'm wrong) but instead that it was simply made for the song.

[blast335]

Alright thanks!