At the time of this post, this trailer is still not out on the official Kamen Rider W Returns website. However, Mitsuru Matsuoka, the actor of Katsumi Daido also known as Kamen Rider Eternal, was holding a live broadcast on Nicovideo. He decided to show this trailer to those who were watching the live broadcast. Luckily, I was able to record it in time and get it up on YouTube.

There has been rumors about the plot of this movie since way back in November. Which stated that the second V Cinema movie would be a backstory about Eternal and NEVER going on a mission revolving around Espers. A prototype Eternal Memory would be used, but due to it being unstable it turns the user into the “Red Flare”. The rumors also stated that Utopia Dopant would show up as well as a new Dopant called “Eyes Dopant”.
Most of it seems to actually fit in with whats confirmed to be true. The Gaia Memory at 0:53 is shaped like an E which could possibly be the Eyes Dopant. Kamen Rider Eternal’s logo also goes from red to blue, which might indicate that the Red Flare is true.