SeaSnake
OG
I can't remember if Arya even knows it, but Ned getting killed and everything surrounding that is pretty much Sansa's fault. She's the one that tipped Cersei off to what Ned had planned. If not for her, there is a good chance the Lannisters would have been done in King's Landing a long time ago.
Nah thats all on Ned. The nigga literally told Cersei he knew about Joffrey. The nigga was retarded