Cyanide had originally been skeptical about Falcon's abilities, but she had insisted on being the one to fire the shot. She had said she didn't want her father to be murdered by anyone else. Cyanide hadn't believed she could—but because he couldn't tell her he did research of his own, he had to go along with it.
But to his surprise… she was actually able to pull the trigger, and hit her target perfectly.
Afterwards, though, when he found her again, she was sobbing in a corner on the rooftop where she sniped from. And it was then that Cyanide knew—she wasn't the same as Cyanide. Not by a large margin. She still had warm emotions. She still felt sadness, anger, frustration. The mask she put on was just sturdy enough to hide all of that.
Cyanide? He didn't wear a mask. He WAS the mask.