I watched Cardcaptor Sakura, xxxHolic and Tsubasa: Reservoir Chronicle a long time ago, but I still don't understand the relationship between them.
I don't understand this: http://tsubasa.wikia.com/wiki/Crossover_Universe, who is whose father, who is who in an alternate universe, etc.
Can anyone give a character tree with details?
I can offer some details on Xxxholic, as I'm more familiar with that one than others, though I've also read all of Cardcaptor Sakura and the majority of Tsubasa REservoir Chronicle.
Clow, who is deceased at the time of TRC and Xxxholic, is an ancestor of Sakura's (with no indication of how far back that is). Clow is sort of reincarnated in two characters in CCS, one of whom is Eriol (little kid with glasses who looks like a chibi Clow). The "original" Sakura and Syaoran, from CCS, grew up and married and apparently felt their son (I haven't seen any conclusive name, but he's a boy) was in danger, so they split him into "clones" (could be a bad translation) and sent each into different universes. Two that I know of are named Syaoran, and both show up in TRC. Watanuki from Xxxholic is a third. I don't know of any more, but I haven't read the entire CLAMPiverse and they're still writing. I can't draw a family tree here but if it were tipped on its side:
Clow
|
(unknown generations)
|
Sakura = Syaoran
|
|--------------------
| |
Watanuki "Other Syaorans"
It's highly unlikely Clow and Yuuko had a child together. I get the impression she's quite old (her clothing, pipe and furnishings suggest late 19th century at the latest) but she seems not nearly as old and certainly not as powerful as Clow. Yuuko and Clow made Mokona (both of them) foreseeing they'd be needed for communication between Yuuko and the TSC main characters.
I hope this helps a bit.
The other answer is wrong; the Sakura and Syaoran from Cardcaptor Sakura are not prominent characters in Tsubasa (though Sakura makes a cameo). Here's a picture to illustrate the familial relationships in Tsubasa and xxxHolic between the three Sakuras and four Syaorans who do appear:
Black lines are the obvious familial relationships, dotted blue lines are the clones, and the arrow green lines show reincarnation. Special note: I've used a normal black line to show Fujitaka adopting Fake Syaoran. This allows me to cover up the fact that I don't understand Fake Sakura's relationships, as I wouldn't know whether to use an adoption notation for her or not. As of right now, I am also uncertain whether the altered Clow Kingdom characters are actually the same as the original Clow Kingdom ones (There's complicated time travel stuff going on). See below for an explanation on the different Sakuras and Syaorans.
The Sakura and Syaoran from Cardcaptor Sakura are not the same as any of the Sakuras and Syaorans who appear in Tsubasa. I know this for two reasons.
The real Syaoran of Tsubasa is the son of the reincarnated fake Syaoran and fake Sakura. Fei-Wang Reed uses real Syaoran and real Sakura to create the fakes, the fakes die and are reincarnated in the past, creating a cycle. Real Sakura has the right parentage as her Cardcaptor Sakura counterpart, but she lives her life in the alternate reality of the Kingdom of Clow. This precludes the fakes or the real ones from being the Sakura and Syaoran from Cardcaptor Sakura due to their parentage not matching up in Syaoran's case, or world in Sakura's. The reincarnated fake Sakura and fake Syaoran might be stronger contenders, having lived their lives in a world very similar to Cardcaptor Sakura (a modern Tokyo and Hong Kong), but they are shown to have met later in life than their Cardcaptor Sakura counterparts, when Sakura takes a school class trip to Hong Kong. Their physical appearance matches what they usually look like in Tsubasa, which means when they meet their age is around the same as we see them for most of the series; Fandom sites list this age as fourteen. In contrast, Syaoran and Sakura meet in grade school in Cardcaptor Sakura.
Having firmly established that the two main Sakuras and Syaorans of Tsubasa are alternate reality versions, I can also tell you that most of the characters from other series who appear are alternate reality versions (in fact, I'm 90% convinced Clamp never let the Tsubasa cast into any canonical version of their worlds, excluding xxxHolic, of course). I'll try to go through some characters and explain their place in the multiverse, but I can't go through them all, especially those from series I am not familiar with. Spoilers ahead. Since I think the Sakuras and Syaorans are where most of the confusion is going to be, I'm focusing on them, and I'm using some name designations I think will help.
Cardcaptor Sakura Sakura: Has only a minor role in Tsubasa, and no relation to the Sakuras in the story. Her parents are Fujitaka and Nadeshiko, she has a brother named Toya, and she lives in Tokyo.
Real Sakura: Daughter of Fujitaka and Nadeshiko in the Kingdom of Clow, sister to Toya. Her real name is Tsubasa (Don't ask me what that means. If it confuses you, you're better off with the more descriptive designation I've given her of "Real Sakura").
Fake Sakura: An image/clone Fei-Wang Reed created from Real Sakura. She lives in an altered Kingdom of Clow where Clow Reed is her father. She also has her brother Toya.
Reincarnated Fake Sakura: After Fake Sakura dies, she is reincarnated in the past, where she becomes the mother of Real Syaoran. In volume 24, Real Syaoran states that Real Sakura's mother looks just like his grandmother; thus we can be fairly certain Reincarnated Fake Sakura's parents are also Fujitaka and Nadeshiko, albeit alternate reality versions.
Cardcaptor Sakura Syaoran: Has no role in Tsubasa, as far as I'm aware.
Real Syaoran: He is the son of the Reincarnated Fake Syaoran and Reincarnated Fake Sakura. He lives in a modern world, but his parents send him to the Kingdom of Clow to meet Real Sakura. His real name is Tsubasa, but his father tells him to take his name when he sends him to the Kingdom of Clow (Unlike with Real Sakura, Real Syaoran's name being Tsubasa actually makes sense, given his father is already named Syaoran).
Watanuki (from xxxHolic): When Real Syaoran makes a wish to turn back time in order to save Real Sakura, Watanuki is born to take Real Syaoran's place as the son of Reincarnated Fake Sakura and Reincarnated Fake Syaoran, because that's apparently a consequence of messing with time. He is "another Syaoran". He resembles Clow Reed. And by the end of the series, due to all the wishing and time meddling, it is stated that he and Syaoran become two separate entities.
Fake Syaoran: An image created by Fei-Wang Reed from Real Syaoran. He is thrown into the altered Kingdom of Clow, where he meets Fake Sakura. He is initially adopted by Fujitaka, who is not Sakura's father in this Kingdom of Clow, since Clow Reed is.
Reincarnated Fake Syaoran: After Fake Syaoran dies, he is reincarnated in a more modern world, where he lives in Hong Kong. He meets Reincarnated Fake Sakura while she is on a class trip, and eventually the two of them become parents to the Real Syaoran.
Princess Tomoyo and President Tomoyo: Neither of these is the Tomoyo from Cardcaptor Sakura. One is a princess in feudal Japan, and the other is the president of a company in Piffle World, a futuristic world.
Clow Reed: A version of him appears as the father of Fake Sakura in the past, however he is deceased when the story begins. I have no clue if any or all of the Clows are actually the same Clow Reed mentioned in Cardcaptor Sakura, and I don't think anyone else does either. There's nothing but a lot of speculation on that subject.
Yuko (xxxHolic): She is implied to be deeply connected to Clow Reed. When she was about to die, Clow made a wish to stop her from dying, and ended up stopping her time. Again, no idea if the Clow referred to in Tsubasa is the same as Cardcaptor Sakura.
Fei-Wang Reed: He is an image born as a personification of the wish Clow made to save Yuko.
King Ashura: Given that an alternate reality version of Chi from Chobits and Fai, an original character, are in his world, I suspect this is not the same King Ashura from RG Vega, though I have not read any of the series.
Piffle World Characters: Piffle world is unique, in the characters we see are all alternate reality counterparts to ones we've seen before (and those ones themselves mostly being alternate reality versions of real Clamp characters). Only the world-hopping Kyle turns out to be the one we saw before. I think Piffle World highlights the idea that, yes, these are all alternate reality characters, and not the actual characters from the original Clamp stories.
Fuu, Hikaru, and Umi: These are the classmates of Reincarnated Fake Sakura, who go on the class trip to Hong Kong with her. Magic Knight Rayearth takes place while they are in middle school, and Fandom sites list their ages as fourteen in Rayearth. Sicne Sakura supposedly is fourteen here, they are also fourteen, making their ages match that of Magic Knight Rayearth. In Magic Knight Rayearth they all attend different schools, but they're all on the same class trip here, so it is likely that these are alternate reality incarnations.
X Characters: X characters are featured prominently, often with multiple versions of the same characters appearing in other worlds, such as Piffle World, Oto, and the ruined Tokyo. Update: Having watched the X anime series, I am convinced that none of these characters are the originals. In X, Subaru and Kamui are not brothers, nor are they vampires, and Seishiro and Fuma are not brothers either.
Translator's notes in volume 15:
Clamp fans will recognize nearly all of [...] the Dragons of Heaven and Dragons of Earth from [...] X (X/1999). However, fans will notice that the teams Kamui and Fuma are leading are reversed.
The other X characters don't seem to say anything about this development, so even though the apocalyptic setting is similar to X, these are all probably alternate reality versions.
