This isn't an astoundingly amazing series so far and it's fairly one note. It's essentially wank fodder and wish fulfillment when you get down to it. The artwork is nice enough in that it's neither particularly good or particularly bad. I've seen hentai and ecchi series with worse artwork, but I've most certainly seen series with better artwork.
What will likely drive people off is that the sex isn't entirely consensual. There are female characters that do the "ahhh... no..." lines, but they're done in such a fashion to where they come across as playing hard to get rather than actually saying no. This is later explained by the demons saying out loud that they cannot resist the hero's "sword", which doesn't really resolve the dubious consent issues, although the author does show many of the women demanding sex even when they've been purified.
As for the story, this is probably the series' saving grace. No, that doesn't mean that it has a good storyline. If anything, this is the weakest part of the series since the basic storyline is so weak. This is monster of the day territory where the only goal is to show the hero getting his rocks off. However what salvages things is that the series is hyper aware of this weakness and also aware that their readers are likely just looking at this in order to get off. It plays things up as a gag and even the main baddie has pretty much forgotten her original purpose in favor of becoming infatuated with the main character. If you notice, you'll see that I haven't used any names. Why? Because they're ultimately forgettable. However again, the fact that this series is so self aware about everything makes it surprisingly readable and somewhat cute. The main character's horndog nature is played up for a few laughs now and then when he's shown to be none too discriminating about his sexual partners. In one episode he sleeps with older, unattractive women and in another, a pretty male character- although neither of these two incidents are shown "on camera" like the others were.
This is decent enough to read as a time waster, but there IS better stuff out there if you want to read hentai or erotic series. This is pretty much the thing you read inbetween the good stuff.