Iron Man 3: The Prologue
When Chinese film company DMG Entertainment signed on to partially fund and produce Iron Man 3, it was on the condition that Marvel agree to incorporate Chinese characters into the story. That's how Dr. Wu and his assistant, played by Wang Xueqi and Fan Bingbing, respectively, ended up in the movie. You probably don't remember them because most of their scenes were cut from the film. In the US version, they appear for a whopping 10 seconds, while in the Chinese version, only 3 minutes of their scenes survived the cutting room.
DMG wanted to salvage those deleted scenes, shoot some additional material, and package it all as a Chinese short film tied in with the Marvel Cinematic Universe. The short, called The Prologue, takes place before the events of the first Iron Man, reveals how Shaun Toub's Yinsen and Dr. Wu came to be friends, and provides additional backstory on the creation of the Arc Reactor. The plan was for it to be released as a promotional short on the web, then broadcast on TV, and included on the Chinese Iron Man 3 blu-ray. Given the business Iron Man 3 did in China, any one of those would have been a big deal.
When Iron Man 3 was nearing release, Marvel kept asking DMG to shorten the already completed film. It went from 15 minutes to 12 to 10, then finally 7 minutes. Marvel then killed the whole project altogether (i.e. please shorten it to 0 minutes). It's a shame because a lot of people put in so much work into what they thought was a really cool once-in-a-lifetime project. I know I gave it my very superhero best. Now know how I'd approach a Marvel action-comedy set in China.