If you think training Vikings to coexist with dragons sounds tough, try following up an iconic coming-of-age story within the halls of a publicly traded animation studio. The pressures to make a giant four-quadrant monstrosity must be enormous, and yet, like his unflappable hero Hiccup, “How to Train Your Dragon 2” writer-director Dean DeBlois has prevailed, serving up DreamWorks Animation’s strongest sequel yet — one that breathes fresh fire into the franchise, instead of merely rehashing the original. Braver than “Brave,” more fun than “Frozen” and more emotionally satisfying than so many of its live-action counterparts, “Dragon” delivers. And good thing, too, since DWA desperately needs another toon to cross the half-billion-dollar threshold.

Set five years after the previous story ends, this latest adventure vastly expands the world and characters suggested by Cressida Cowell’s YA book series, which informed the spirit if not necessarily the exact plot of the 2011 film. Once an awkward teen, Hiccup has now grown into a handsome young man (though his voice, still supplied by Jay Baruchel, is as warbly as ever), set to succeed his father, Stoick (Gerard Butler), as chief of Berk. But too many experiences remain, compelling the thrill-seeking Viking lad to spend every free moment away from the tribe, drawn to whatever lies beyond the edges of his map.

For the benefit of newcomers, Hiccup narrates a high-energy opening sequence that, like the matching epilogue, seems tacked on and feels at odds with the rest of the pic’s sensibility, which, as a rule, respects the audience’s intelligence. These two scenes reunite Hiccup’s rowdy classmates — Snotlout (Jonah Hill), Fishlegs (Christopher Mintz-Plasse), Tuffnutt (T.J. Miller) and twin sister Ruffnut (Kristen Wiig) — for a dragon-racing derby, a sport that looks like a cross between Quidditch and pod-racing (a la “Phantom Menace”) and was surely invented to appeal to the same demographic.

As usual, it’s resident tomboy Astrid (America Ferrera) who wins, while Hiccup, now her b.f., is again off exploring with his dragon, Toothless. Clearly, Viking society has taken a significant turn since last we saw it — unless, of course, you’ve been following Cartoon Network’s “DreamWorks Dragons” series, which bridges the two features and details the challenges of human-dragon coexistence. Now, instead of waging battle with flying reptiles, the residents of Berk spend their time putting out fires (literally). After all, the primary drawback of being besties with beasties is that these exotic pets have certain combustible qualities that dog owners don’t have to deal with.

As it turns out, not all dragons breathe fire, something Hiccup and Astrid discover when they chance upon a manmade fort frozen in shards of green ice — the handiwork of something called a Bewilderbeast, just one of many previously undiscovered new species. Compared to the movie’s other badly designed, barely aerodynamic dragons, this awesome lumbering creature looks like it might have been dreamed up by H.P. Lovecraft himself, single-handedly reintroducing the idea of intimidation into the dynamic between men and dragons.

However fearsome this so-called “king of all dragons” might be, it’s men that Hiccup and his kind ultimately have to worry about, for he who controls the alpha dragon controls them all. This development represents perhaps the biggest variation from the admirably villain-free original, in which the conflict resulted from ignorance and superstition, rather than the machinations of a power-hungry meanie. Where the first “Dragon” was a high-flying riff on “Black Stallion,” the sequel shifts genres entirely: Though it still features feel-good horse-and-his-boy bonding (Toothless is more expressive than ever, courtesy of some truly inspired character animation), the story now escalates to a full-blown war movie, pitting Hiccup against a notorious dragon hunter named Drago Bludvist (Djimon Hounsou).

Just as Hiccup has aged, so too has the target audience for the new film, which is dark enough to satisfy the “Game of Thrones” crowd without alienating kids along the way. And where the earlier movie teased the idea of mortality, costing Hiccup a leg in lieu of his life, this time around, DeBlois commits to the idea that dangerous acts have serious consequences: Major characters will be asked to make huge sacrifices to protect the ones they love. In that sense, “Dragon” aspires to join the ranks of epic poetry, resulting in scenes that make “Bambi” and “The Lion King” look like mere cartoons.

In the past, Hiccup has been the franchise’s most enlightened character — the one who teaches others to overcome their prejudices — but here, he is shown in a state of almost perpetual learning. Rather than merely presenting the world on its previously established terms, as so many sequels do, DeBlois constantly introduces new twists to which both audiences and the ensemble must adapt, none more significant than the appearance of a vigilante named Valka (Cate Blanchett), whose gender is but a mere fraction of the surprises she represents.

If Drago is the embodiment of pure evil — a figure who simply cannot be reasoned with — then Valka is his generous, nature-respecting contrapositive. She lives at the center of a visually stunning, dragon-safe sanctuary where winged reptiles of every color swarm overhead. This habitat, which calls to mind those breathtaking monarch butterfly colonies high in the Mexican mountains, surely ranks among the most incredible environments ever depicted in animation, rivaling eco-conscious Japanese maestro Hayao Miyazaki’s creations for sheer majesty.

To discover this dragon-friendly zone alongside Hiccup is a rare and special experience, which is to say nothing of the many personal revelations in store for him here. This may as well be his Fortress of Solitude, or to borrow an analogy from that greatest of fantasy-movie sequels, “The Empire Strikes Back” (whose influence on DeBlois cannot be underestimated), it’s the spiritual equivalent of Dagobah, where Yoda trains Luke Skywalker in the ways of the Force.

Together with Astrid, and later joined by his father and comic relief Gobber (Craig Ferguson), Hiccup comes to discover much about both his past and his destiny in this space. DeBlois could have played the sequence a million different ways, which makes it all the more stunning for him to “let it go” as he does, turning to an original Celtic-style ballad, “For the Dancing and the Dreaming,” sung as an intimate duet between two characters, instead of belted Broadway-style from the rooftops. If necessity is the mother of invention, then DreamWorks’ desire to extend the “Dragon” franchise has propelled the creative team in the most admirable of directions, resulting in what just may be the mother of all animated sequels.

Film Review: ‘How to Train Your Dragon 2’

Reviewed at Cannes Film Festival (noncompeting), May 14, 2014. (Also in Taormina, Annecy Animation, Los Angeles film festivals.) MPAA Rating: PG. Running time: <strong>102 MIN.</strong>

  • Production: (Animated) A 20th Century Fox release of a DreamWorks Animation production. Produced by Bonnie Arnold. Executive producers, Dean DeBlois, Chris Sanders. Co-producers, Kendra Haaland, Doug Davison, Roy Lee, Michael Connolly. Co-executive producer, Kate Spencer Lachance.
  • Crew: Directed, written by Dean DeBlois, based on the "How to Train Your Dragon" book series by Cressida Cowell. Camera (color, 3D); visual consultant, Roger Deakins; editor, John K. Carr; music, John Powell; production designer, Pierre-Olivier Vincent "POV"; art director, Zhaoping Wei; sound (Dolby Atmos, Datasat, SDDS); supervising sound designer, Randy Thom; sound designer, Al Nelson; supervising sound editors, Thom, Michael Silvers; re-recording mixers, Thom, Shawn Murphy, Brandon Proctor; visual effects supervisor, Dave Walvoord; head of character animation, Simon Otto; head of layout, Gil Zimmerman; head of story, Tom Owens; character designer, Nico Marlet; stereography, Willem V. Drees; associate producer, Aaron Dem; casting, Leslee Feldman, Christi Soper Hilt.
  • With: Voices: Jay Baruchel, Cate Blanchett, Gerard Butler, Craig Ferguson, America Ferrera, Jonah Hill, Christopher Mintz-Plasse, T.J. Miller, Kristen Wiig, Djimon Hounsou, Kit Harington.