Definitely an interesting vibe from the poster. I wonder if Rui is some kind of digital being; it's an underexplored area in the franchise. October 27th is pretty soon! Might just hold out for a dub like I did with Kizuna, but we'll see...
As interesting as that would be, it would place him in the same category as Gennai, right?
I have mixed feelings about the premise of the film. If he's the first person to ever be partnered to a digimon, doesn't that come into conflict with Maki and Co.? Not that I want to beat a dead horse, but I personally don't want them dealing with the origins of the digital world, and partnerships within the Adventure continuity given how Tri and Kizuna handled the subject. What was once "unique" to our core crew of 8/9 (? If we count Ken!), came to be undermined by Menoa, Maiko etc. Maki and Co. being the exception, because Adventure 01 acknowledged a previous crew of Chosen Children, but partners being common prior to the events of the Omnimon web event seems to undermine everything about the series. Why the Chosen Children from Japan vs. the sprinkling of partnered children the world over that were their contemporaries? Regarding the latter, I mean those figures which are shown to have such a significant impact on the story of Adventure from outside Japan.
There's actually an explanation for there being Chosen Children prior to Taichi and the others. An interview with the series director Hiroyuki Kakudou (see
here) revealed that the number of Chosen Children had been doubling every year, and that there were 16 total Chosen Children in 1999. Working backwards, there had to have been 8 in 1998, 4 in 1997, 2 in 1996, and 1 in 1995. We can assume Rui was the original in 1995, with the other 7 logically being Wallace, Menoa (who we know had to have met Morphomon in 1997), & Maki's group of 5.
There are two big contradictions to this though. Wallace is said to have gotten his Partners 7 years prior to 2002, which should be 1995, but that would contradict there only supposed to be 1 Chosen Child that year. The other being that the Maki and Daigo's fight against the Dark Masters had to have taken place in 1998, and in the flashback they look to be the same age as Taichi, but they are both clearly older than Taichi in
tri.
Out of universe, the Hurricane Touchdown and
tri. were not overseen by Kakudou, so there were bound to be some contradictions. In universe, I've got a headcanon for the Maki situation, and as for Wallace, maybe he didn't get his Digivice, and thus actually become a Chosen Child, until 1996?