“Sweet as sugar. Hard as ice. Hurt me once. I'll kill you twice.”

“Give me a half-tanker of iron, and I'll give you an ice-age.”

“She slapped Kestrel's face. Without thinking twice, Kestrel slapped her back, as hard as she could. The young woman burst into tears. The servant saw this, aghast. "Baby!" she exclaimed. "Oh, my poor baby!"
"You've been kind to me," said Kestrel, "and you're very beautiful, but if you hit me again I'll kill you."”

“I think I was once given cocaine but I sneezed so it didn't go up my nose. In fact, it may have been icing sugar.”

“It’s hard to kill a creature once it lets you see its consciousness.”

“I know it's hard for you to trust me. If I ever find the man who did this to you, who made you so frightened, I'll kill him with my bare hands. But you can trust me.”

“Besides, you think I'm not used to hurting? For me, it's home sweet home, my brother.”

“Hey, Mikey? You get her hurt and I'll end you."
"You let anything happen to Eve and I'll do the same," Michael said. He'd just finished kissing Eve, too. "While you're at it, don't get yourself killed, either, bro."
"Ditto. And don't kiss me.”

“Kill you all!" The clown was laughing and screaming. "Try to stop me and I'll kill you all! Drive you crazy and then kill you all! You can't stop me!”

“Is this the part where you say if I hurt her, you'll kill me?"
"No" Simon said, "If you hurt Clary she's quite capable of killing you herself. Possibly with a variety of weapons.”