Haven't seen this topic yet, so...
Despite all the worlds visited there's still a lot of famous/popular characters that have yet to make an appearance. Therefore which CLAMP characters, who haven't shown up yet, do you want to see the most?
And...which CLAMP character (who hasn't shown up) do you think will pop up next?
The ones I want to see the most are:
Hokuto (Tokyo Babylon) - we seriously need a vampire version of her, simply so she can scheme to get her brother and "Sei-chan" together, hehe. Also it'll explan how Subaru can dress so cool.
Kujaku (RG Veda) - Love him and I think he'd fit in well on Celes as I like to think of that world full of mysterious, powerful people. We've seen a lot of RG Veda characters thus far but no Kujaku so I hope they're saving him for something big.
Fuuma (X) - Alright I know Fuuma has appeared in the current world (Tokyo) but I'm not counting it since really it was only a cameo and I expected more since he's the second most important character in X (and as of right now it appears his Toyko self isn't going to be involved in the story). I mean it's Fuuma! He's too good for a tiny cameo! What I'd really like to see is a vampire version because having Kamui without Fuuma is like having Fye without Kurogane, Subaru without Seishirou, Sakura without Syaoran, etc, it's just something you don't do!
As for who'll show up next, I really have no clue; I'm still a CLAMP newbie. I'm thinking of someone from Wish though since I was looking at the crossover list and saw no one on it from that series. I couldn't say who though since I haven't read Wish yet.