Cockblockers are our protective roles. The Booty Caller speaks to the dead. All of the roles seem to work a little differently even if they have similar rules. That's what I'm finding out.

But, more likely, Edelgard probably slept with Katy and knew that if Katy was picked she'd be saved. That's how Edelgard's works. It's also why Escha tried to frame Tamamo.