This is fantastic! I remember loving Nira Oni when I was younger so seeing it still get love is great :D
I do just wanna mention something annoying I encountered while trying to get the good ending that I feel like needs to be changed/fixed (SPOILER WARNING!!)
If you have blood disabled, the key that allows you to get Cassey's Voodoo Doll doesn't spawn. I don't play with blood disabled normally, I only hit it accidentally that time, but still something worth bringing up.