User blog comment:SuperGaming101/Question of The Week: Who is your favorite most threatening evil villain so far?/@comment-2189621-20170107072958/@comment-27853587-20170110053924

You do not want Evil Chell to come back without GLaDOS.

If that happens, you have 6 minutes to kill the unkillable before your heart/other vital organ gives out and you die. The exact same thing happens to all the characters.