Unmarked spoilers are ahead, per Spoilers Off rule.
In Chapter 23/Episode 21, Syaoran embraces Sakura while saying that he will never let misfortune fall upon her. While it can heartwarming, the reason behind it is because the Clan and Eriol told him that great power will bring great misfortune. And there was been several implications that Syaoran will be willing to do self-sacrifice just for Sakura's sake.
The backstories of both Akiho and Yuna: Akiho was born into a magic clan with no magic of her own, resulting in the clan rejecting her. And then, thanks to a passing comment from Yuna, saying that Akiho was like a blank book, her clan then decides to turn her into a living spell book, slowly filling her up with spells that would slowly destroy her soul. Yuna’s guilt and his desperation to give Akiho a better life makes very much sense, as he knows that his careless comment was what condemned Akiho to such a horrific fact, and if nothing was done, her clan would destroy her soul for their own benefit.
