Try Amazon. That's where I get all my manga.
If you foolishly still insist on me telling you, despite the fact that it could ruin the scenes in question for you, then fine.
Spoiler:
Yuki was attacked and nearly killed by Angie. He claimed some deranged reason for it, making himself sound like a psycho-obsessive lunatic for Akira, but I don't believe it, now that volume 9 has revealed that he's been working for Telomere for some time, quite possibly since before the ritual ordeal with him, Akira, Graham, and Sanin. Yuki, I believe, was an incidental target, attacked mostly to eliminate her as a witness to the actions Angie had taken in going after his real target. Surprisingly, the woman he was after escaped unharmed.
Yuki was seriously injured, causing blood to build up between her skull and her brain, putting pressure on her brain. It would have killed her if Duke Borgiani hadn't come up with the idea of using the Tepes version of the Pied Piper nanomachines to drain the blood and repair or replace the damaged portions of her brain. Yuki survived, but she is still recovering, and has been unable to speak since then. It's possible she may fully recover: there just hasn't been enough time to tell.