Why become Li Cuiyu? Isn't the original identity of Lin Junyun usable?
It can only be because the abducted ones are not easy marks. Lin Junyun doesn't possess high value as a captive; wouldn't Cao Yu and the others be suspicious if she were abducted?
These people are already suspicious of every companion around them.
So, Lin Junyun's identity is not usable.
But Li Cuiyu's...
"The person most likely to be silenced can indeed reduce the vigilance of Cao Yu and the others..."
Yue Beiqing looked down, "Especially the vigilance of Pu Qinghan."
Women are generally less guarded against other women.
Especially when everyone is trapped, regardless of previous disagreements, as long as they find themselves in the same dangerous situation, they tend to band together due to human nature.