|Maybe Ningyo no Mori This one is pretty good, my all time favourite, its a bit dark though.
Kieli This one is a bit dark too, but it fits your description and its really good.
Kanata Kara My personal favourite and it fits the description.
But if it makes you happy to win on the internet, have at it.
Screams from the haters, got a nice ring to it. I guess every superhero need her theme music...