The strangler is a rare poison, which makes the person unable to breathe. The poison is made from plants that are only found on islands in the Jade Sea. The leaves of the plant are picked and aged, then soaked in a wash of limes, sugar water and rare spices from the Summer Islands. The leaves are then discarded, but the liquid is kept and thickened with ash and allowed to crystallize. It turns a deep purple color.
“People don’t like her because it’s the making of her, right now. When she, sometime soon in the future, becomes this person that she’s been kind of building up to, for the past three seasons, now four, then people will really begin to root for her. I think even the audience doesn’t realize she’s such a dark horse. If she acted badass and tried to kill everyone there, she would be dead by now! She’s so intelligent, and I can’t stress that enough. Courtesy is a lady’s armor. She’s using her courtesy to deceive people, and she’s using her former self as a facade, and it works so much to her advantage, because people still think she’s this naive, vulnerable, little girl, and she’s really not. She knows exactly what she’s doing. She knows what game she’s playing! And no one else does. And she’s learned from the best — Cersei, Margaery, Tyrion, Littlefinger, even Joffrey. She’s learned so much from these people, and they don’t even realize it. They’re unwittingly feeding her to become this great kind of manipulator. King’s Landing can either make or break a person, and in Sansa’s case, it’s making her.”