And they most likely paid to use the IP, which they can allow. You can make parodies and products with it, if you have a contract for it, like how EA publishes SW and Marvel games. I doubt Kapparu has one though. In this case, Kapparu is using a copyrighted brand that belongs to someone else, without having a permit for that, and makes profit off it.
Disney bought Marvel in 2009. The first Avengers porno (there are sequels) was released in 2012.
Do you REALLY think Disney is going to license the Avengers to Vivid to make a porno? NO FUCKING WAY!
Vivid has done Avengers, X-Men, Superman and Spider-Man. Maybe more. Did they get licenses from Marvel, Sony, DC and Fox? I seriously doubt it. (Yes, Marvel owns the Spider-man rights now, but Fox held them when Superman vs Spider-Man was released in 2012.)
Then there's the last paragraph of this PR statement:
You must be registered to see the links
"
Disclaimer:
Avengers vs X-Men XXX: An Axel Braun Parody is a parody movie. All characters and related materials are trademarks, copyrights and/or registered trademarks of their respective license holders and/or owners. The parody movie is not sponsored, or endorsed by, or affiliated with Marvel Characters, Inc. or its affiliates or parent company or any other company owning the trademarks of characters seen therein."
The Vivid press release SPECIFICALLY states that they don't have rights to the characters.