(Spoilers) The kind of sequel made by people who don't like sequels.
I thought about this recently: why would anybody make a sequel like this? They start out with a great premise, and then ruin it. They "kill" off the principal character, the protagonist of the series, the one you fell in love with in the first movie. They basically give her the worst end she can possibly imagined. Meanwhile, the relationship between the sisters, which was the very heart and soul of the first movie, is thrown away by the end. Instead, the movie switches subjects in the very middle to Ghost, pretty much saying they were bored.
The producer, Steve Hoban, says that he would be interested in continuing the series with Ghost, which is the equivalent of saying that he wants to change subjects, too. They might as well put a different name on the series if they do that.
The more I think about it, the more I think this is a movie you make to kill off a series and confound people who would have liked it continued. And it has done both.
That goes double for the prequel.
Is Unleashed good, then? In that it still delivered a story and otherwise did what the people in charge of it wanted it to do? Yes.