Nora West-Allen: As a kid, there was part of the Flash Museum that always scared me. I guess it's normal for children to be afraid of monsters. But this monster was different. No one knows where he came from, how he got his powers, who he is. All that's known is his alias, and the last sound his victims hear. But that's not what makes him scary. What makes him scary is... you can never catch him.
Barry Allen: We never catch him?
Nora West-Allen: Supergirl, the Legends, even the League tried, but no one was successful.
Ralph Dibny: Probably he can dampen everybody's powers with that magic friggin' dagger.
Caitlin Snow: Not all superhumans are meta-humans though. What about...
Nora West-Allen: Green Arrow? Yeah, he tried too once, but...
Cisco Ramon: So we're dealing with a meta-human Jack the Ripper. Amazing.