It’s actually an OK possession / exorcism movie for the most part, until the ending. In the ending, the quality drops down significantly – idiotic cumbersome fight along with amateur editing, really poor visual effects with samely poor camera work. Not to mention the ridiculous ending scene.
I don’t know what happened, but until that point it was a decent indie movie with great casting, good acting and some memorable scenes (like the sex scene). Seems to be one of these many, many indie movies whose creators just can’t end their movies so they come with something fast and just call it a day.