Good spiritual medium
I wonder if the excorcist worked on banishing Kayako would it have worked because she can't hide and masquerade as a look-alike.
"I think I liked it better when I thought Sylar ate brains."
It is weird no one attempt to it.
But remember Kayako is an extreme powerful spirit. This young woman, the girl's aunt, couldn't beat Kayako. It takes someone way too much stronger and experienced.
Please excuse my terrible redaction, english is not my native language.