Guillermo Del Toro on Pacific Rim: We built several blocks of Hong Kong to destroy, and then we destroyed them!

Every time we see a new glimpse of Guillermo del Toro's monsters-vs-robots movie Pacific Rim, we get more and more thrilled and astonished. Del Toro just came to Wondercon and showed us a special trailer for his film – including the birth of the Jaegers. And he gave us an update on his Justice League Dark movie!

We saw some brand new bits of footage from Pacific Rim, including the earliest attack of the Kaiju on San Francisco, and we see Charlie Day from It's Always Sunny in Philadelphia explaining that if we want to stop the kaiju we have to understand them. To which Charlie Hunnam responds, "Or we could just blow them up."

Charlie Day explains that the kaijus' purpose is to head for the populated areas and wipe out the vermin, meaning humans. He helps to create the giant robots, boasting that they are 2,500 tons of awesome. We see huge scaffoldings and workers toiling to create these huge walking WMDs.

The Jaeger robots make huge victories against the kaiju at first, and it seems like the human race is winning the war – and then the kaiju strike back, and humanity suffers a great setback. We see a kaiju jump onto a robot's head and grip it like a wrester. We see Charlie Hunnam stumbling his suit torn from the wreckage of a Jager. This is when the human race has to rally, and Idris Elba has to tell a crowd full of suffering people that we are cancelling the apocalypse.

We see a Jaeger being punched so hard it falls in mid-air... we also see the Kaiju attacking a city of 2 million people, and a Jaeger stalking across the cityscape towards it. The Jaeger hoists a giant tanker boat as a weapon and swings it like a baseball bat, and hitting the monster in the head with both fists, so hard it s head practically explodes.

We also caught a glimpse of Ron Perlman as a sleazy blackmarket dealer, who deals in bootleg Kaiju organs which can cure all human ills, including erectile dysfunction.

Del Toro told us that the most important thing for him in this movie was to "convey to an audience... a sense of awe and scale, [with] 20 story high motherfuckers kicking the hell out of each other" To that end, he occupied every stage, including the largest stage in North America, Toronto Pinewood Studios, and then spilled over.

"We built several blocks of Hong Kong to destroy and then we destroyed them," said del Toro. "We built the head of a robot with the machine, the hydraulics, everything in it – four stories high." The actors stood inside this four-story robot head and every time a monster hit the robot, the entire set would rock back and forth, "which made the actors very happy."

Guillermo Del Toro on Pacific Rim: We built several blocks of Hong Kong to destroy, and then we destroyed them!

Everything was done with real actors, not stunt performers, as much as possible, and the physical machines that controlled the robot were actually attached to the actors, rather than being done with CG. In essence, said del Toro, the actors had an apparatus the size of a VW Beetle behind them, which they had to carry. "At the end of the day, they were exhausted and destroyed physically, and I was sipping my fourth cappuccino." The only actor who didn't break down under this strain was Rinko Kikuchi – del Toro asked her what her secret was, and she said she thinks about gummy bears and flowers.

The filmmakers also built one foot of a Jaeger, that was at least the size of the auditorium where we were watching the footage.

Del Toro praised Ron Perlman's performance as blackmarket dealer "of the lowest kind" Hannibal Chau, whose name is his favorite historical figure, plus his second-favorite Sichaun restaurant in Brooklyn. "He chews the scenery."

Meanwhile, though, Charlie Day told del Toro that he didn't want ot be overtly comic in his performance – he wanted to play it seriously, and then let the comedy come out of the situation. Del Toro was absolutely okay with this, and in fact Day has a monologue that's two and a half pages long, and he absolutely nails it. Day's character, Dr. Newton Geiszler, is a scientist who's sort of a punk-rocker, with tattoos and piercings, but also a supergeek who describes monster parts as being in "mint condition" as if they were collectibles. His look goes from Rick Moranis to J.J. Abrams.

Del Toro said they designed tons of robots and monsters, and had a kind of American Idol-style competition to see which would be featured prominently in the movie. And for each of the robots, they had to figure out all of the details – where would the nuclear reactor be, what other power source it might have, where the pilots would go, and what fighting style it would have. The poster features the Russian robot, which has a "set of incredibly powerful hydraulic presses" in its fist, so when it punches the hydraulics push the punch home.

Del Toro always wanted to feel the weight of the robots moving around, they had to move like things that weighed thousands of tons. "You needed to feel the compression of the hydraulics" and the massive size coming down. Del Toro has seen the movie countless times, but he still has a "shit-eating grin" every time he watches it. He is "absolutely in heaven."

Guillermo Del Toro on Pacific Rim: We built several blocks of Hong Kong to destroy, and then we destroyed them!

Del Toro also showed us this cover of his prequel graphic novel, Pacific Rim: Tales from Year Zero (above – click to embiggen), which delves more into the early days of the conflict. We learn more about the mythology of the alien race that sent the Kaiju, which is a race that basically eats planets. The cover shows one of the early robots, a Mark One, which is "much more rusted," and more of an old-style robot, like from a 1940s style science fiction book cover.

During the audience Q&A, someone asked del Toro about the Justice League Dark movie that he told io9 about a while back. He responded:

The next movie I'm shooting is probably Crimson Peak, which is a Victorian ghost story [. . .] on Justice League Dark or Dark Universe, we finished the Bible and we're going to start the screenplay with a writer I'm hoping we can announce very soon [. . .] the lead character who guides us through that is Constantine [who is] blond – and he is basically going trying to recruit these guys for example Etrigan, and Forever Knights. And [we explore] the idea of Jason Blood being part of the knights at the type of Merlin, we [reveal] their origins through the story [. . .] We don't make the origin story at the top [of the film], we find it out as they each have a mystery to solve [. . .] Swamp Thing is at peace with who he is, but Deadman still has to find out who shot him, but these things are woven in [. . .] but when I was a kid my two favorite characters in the entire DC Universe were Trigan and Swamp Thing [. . .] god willing it will happen.