User blog comment:Dim1/What should the next Featured Article Be February/@comment-3551173-20130124192249/@comment-4875978-20130129132047

I haven't read that volume since the first time 6 months ago, but if I recall correctly, Yuuki explains that they wanted to leave their mark because they were going to dissappear.

The sleeping knights were formed from patients in terminal care, but two of them were miraculously healed just before Yuuki's funeral.