Re: Ryo, i like the idea of some original Akiyama Ryo existing at some point and something happening to him get fragmented into pieces, sais pieces going to different universes and timelines, resulting in the phenomenon where there's not just original one anymore but fragments of him.
I love space-time stuff (i mean, i have a whole story about Advverse and its different timelines + other worlds lol) so this is catching my attention 👀👌
I think that's one way to handle it! The last post probably made me come off as harsher on the games than I really intended to be (it's mostly that I know too well Bandai hasn't really had a good track record of being prudent about issues like these), but from a fanfic writer's perspective, sometimes the fun itself comes from taking difficult-to-figure out parts of canon and using it as a challenge of sorts.
If you do want to take Ryou being the same character in 02 and Tamers at "absolute" face value (that is to say, about as closely as the way the games obviously want you to take it, in its most literal form), the challenge becomes a question of how an amnesiac Ryou ends up adapting himself to the Tamers universe. Then you have concepts like the one you mentioned where the universe explosion at the end of D-1 Tamers scattered "fragments" of Ryou across the multiverse that integrated themselves into them, like Tamers' or V-Tamer's timelines. Or you can just take the games' plotlines as a "suggestion" and do whatever you want with the rest of it. Even if you're taking the games at the most face value as possible, you're probably still making concessions here and there to make it integrate with anime timeline, so the question is really just going to be about how much.
Personally, I haven't really settled on a definitive personal headcanon on what's going on with Ryou because I have multiple ideas and haven't been able to make a decision about which one(s) I want to commit to or develop further in my head, but the part I do end up no-compromise is that I'm really not a huge fan of any aspects of the games that derail anime characters' characterization (Ken and Wormmon in Tag Tamers and D-1 Tamers, the Adventure kids' characterization in D-1 Tamers, et cetera), so those are the aspects I tend to ignore or do away with the most. Likewise, a lot of the fanon that Ryou left the Adventure universe for the Tamers one because he was jaded and bitter has to do with interpretations of the fallout from the D-1 tournament, and since that's the part that I have the most discomfort with I tend to not really favor that line of thought (I don't begrudge anyone else who likes that, angst is very juicy after all, I'm just not personally comfortable with it).
The other big question is the fact Ryou is part of 02's media mix, and 02 canonically aired in the Tamers universe (that 02 is involved is confirmed by staff notes and later Digimon crossover works) but nobody in the Tamers world seems to know or care about the fact a popular fictional character is real, but the easiest way around this is that the "Adventure and 02" and Digimon franchise in the Tamers universe already has obvious differences from the real one, so the WonderSwan games and 02 tie-ins presumably didn't happen in the Tamers world's version of the franchise. That said, Millenniummon being a time-and-space distorting entity makes it very easy to come up with other reality-bending shenanigans or explanations, so you really have a lot of options.












