The first half's good, although the second half's more pornographic and less interesting. I watched it all, from beginning to end, which I wouldn't recommend with most hentai. (The art's fairly cartoonish, though, so it'll be of limited use as pornography.)
Julie's being possessed by evil magic. She's betrayed her party members, including Lise (an elven high priest) and Aria (a knight). She can command naughty tentacles, create sex duplicates of herself and grow a penis to use on Aria... but that was an 'in media res' opening, after which the episode goes back in time to show how this happened. Their country's prince gives Aria a mission. There will be tentacles that can dissolve swords and shatter armour.