Worlds
Default muse: Post-Tsubasa (spoilers may lie around throughout this blog)
After the events of Tsubasa: Reservoir Chronicle, Syaoran has set himself to become a dimensional traveler in hopes to find a suitable body for his father. Mokona, Kurogane and Fay accompany him on his voyage.
The possibilities of interactions are endless, seeing as this muse simply ends up in another world, perhaps (and most likely) separated from the others, which gives him a goal wherever he may end up: find his companions once more, research the current world merely for the sake of knowledge, or find a suitable body for his father to live once more.
-Anytime within the events of Tsubasa.
Another option is to pick a point within the manga/anime timeline and develop from there, as this muse has two possible iterations within the storyline.
-Card Captor Sakura verse
For those of us that would be nostalgic about the manga or anime that is another of the alternate universes. It should be noted, for the non-initiated, that the Syaoran from CCS and the one from Tsubasa are not linked to each other.
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Concerning Tsubasa World Chronicles, I intend to keep up with the manga scanlations (and buy it once it is released by Pika Editions most likely!) and as such it will also be an option.