@BaGamman The story never gave this kind of impression though. Both of them is also very young compared to other youkai like the Tengu. Kurona is just a Nekomusume. There are different type of bakeneko and Nekomusume isn't particularly powerful. If you watch or read Gegege no Kitaro, there is also a Nekomusume and she is also not very strong. Bakeneko are also not nearly immortal. All youkai and God have a lifespan too and they can be wounded and killed. In the anime "Ayakashi: Samurai Horror Tales", the MC killed a very powerful Bakeneko.
Komainu aren't divinity. They are just God (Kami)'s servants and not that much different from youkai. In Japanese folklore, a God's power is depended on the number of people that believe in them and worship them. The Komainu's power in turn is depended on the God. Koma lost her shrine and her God, is now freeloading at another shrine which already has other Komainu guardians so she isn't that powerful.
Also, that youkai is an Ubume, the spirit of a woman who died in childbirth. Ubume is considered a very dangerous youkai.