Vin Diesel told fanboys on Friday that there would be some “very big news coming out at the end of the month” after he was asked whether he was about to join the Marvel fold as Vision.

The star was about to round off Universal’s Riddick panel in Hall H when he was surprised by the question from a member of the audience “That’s the one thing I’m not supposed to talk about,” he said with a tortured expression.

Rumours have circulated recently and Diesel has fuelled the flames with playful posts on social media platforms. Marvel hosts its panel on Saturday.

Diesel, co-star Katee Sackhoff and Riddick director David Twohy entertained attendees with footage from the upcoming Universal release on Sept 6. One scene depicted a shackled Riddick being taunted by mercenaries who are unknowingly being stalked by ferocious aliens.

Twohy, who wrote and directed Riddick as he did on Pitch Black in 2000 and The Chronicles Of Riddick in 2004, said the new film was a sequel to both its predecessors and jumped into an account of how it came about.

“Once we realised we were not going to be a studio picture and we were going to be an independent picture it was very daunting and very liberating,” he said.

“We finally settled in on a survival story. I wrote a spec script, we took it to Berlin, we sold overseas markets [through Lionsgate International] and got Universal to come back as domestic distributor.”

New cast members Sackhoff plays the mercenary Dahl. “She goes to hunt Riddick and comes to realise that while he is the most dangerous thing on the planet he is not necessarily the worst thing on the planet.” Diesel said of his character: “He is driven by some quest for identity”, adding later that Riddick was “so scary.”

Prior to the Riddick panel Universal brought in talent from the upcoming release of Kick-Ass 2. Writer-director Jeff Wadlow introduced a bulked-up Aaron Taylor-Johnson, Christopher Mintz-Plasse and several new cast members.

While Kick-Ass forms a crime-fighting team, Mintz-Plasse’s Red Mist persona appears to drive a large part of the story as he plots to avenge his father’s death and assembles a deadly team.

Chloe Grace Moretz spoke via video link from Boston and said that in the new film her character Hit-Girl attends high school as Mindy Macready and fights injustice of a different nature out of uniform.

The memory of Hit-Girl’s late father hovers over the character in the sequel. “His presence in the movie is still very strong and you still feel this looming presence of Big Daddy… he is always there in her mind.”

Moretz said she was drawn to characters who were “super opposite” to herself and referenced her lead role in the upcoming Carrie reboot. Universal will release Kick-Ass 2 on Aug 16.

Immediately prior to the Universal panel, Kristen Bell and her Veronica Mars co-stars and create Rob Thomas took to the stage to show footage from the upcoming film and talk up the Kickstarter campaign that brought the project to fruition.

The private detective tale is set to wrap on Monday following a 23-day shoot and Thomas said he expected it to open theatrically early in 2014. Approximately 91,500 fans donated money to the production, which raced to $2m in its first day of fundraising.

Focus Features’ The World’s End panel featured much banter from director Edgar Wight and stars Simon Pegg and Nick Frost. The film screens at Comic-Con on Friday night and opens on Aug 23.