Picking up where the first film left off, at least in terms of the investment from the audience, “How to Train Your Dragon 2” is what we always hope sequels will be but rarely are. In truth, sequels are trending a little better than they used to, but second-parters are still a damaged brand. In this instance, though, it’s more of that great 3-D animation, the return of familiar characters, some storyline maturation, and a few carefully chosen new additions who don’t overtake what we loved about the first film. With the help of his best friend/pet dragon, Hiccup (voiced by Jay Baruchel) has to battle the nefarious Drago Bludvist (Djimon Hounsou) in order to save all the dragons from enslavement. Bludvist is a particularly harrowing villain for kiddie movies, but it’s another in a long list of things this sequel gets right.