Well, we don't need to know much else, we already know this is when C!Syaoran was made.
Splash Page: Watanuki wearing Clow Reed's cape.
Yuko and Fei Wong talk. Fei Wong comments that the new boy looks like a child Clow. He also says Yuko has interfered again. He attempts to take Watanuki, but Yuko intervenes. This child has the same existence as Syaoran but he is somebody else. Fei Wong remarks that his wish will be granted. He then says that misery awaits the child's parents. Yuko tells the child not to listen. Fei Wong takes Syaoran, stating he will create another, since he can't use Syaoran or Watanuki. As Watanuki opens his eyes, Syaoran yells "Don't disappear!"