It's been done in movies before. A character has their finger on a "destroy everything" button and tries to wait till the very last second for the hero to show...and the hero doesn't, until it's nearly too late.

Fortunately, depression lacks the anger needed to fuel that kind of need for vengeance. Liu Xi just figured that if the heroes were all dead, and she was all that's left, she's going to take out the universe before The Moderator can keep it. Ironically, the Hooded Hood would have been proud.

I'm kind of surprised nobody asked more about the Doorman and Liu Xi encounter. It's one of those things that might be embarrassing for them both once they are freed in the future.