Immoralist is probably my second favorite song this season (Daydream Syndrome from Yumekui Merry is number one, the full version is fantastic; they dumbed down the quality and some of the instruments/bass on the anime's TV size, you've gotta hear the full thing to really appreciate it, plus that singer's vocals are great).
The only thing I hate about Immoralist is the placement of certain sections of the music. I feel like the big chanting part with her "TA~DA~" near the end should've just been followed up by repeat of the original chorus instead of that long-winded drawl to a soft finish they put in there. She says "todoke" so many times that she probably got tongue-twisted when she was recording it.
The composer just crammed too many ideas into one song, is all. Not really Horie's fault. At least she sings all of it well.