Shierak Qiya

There is not much to separate Cersei from Arya. Both psycho girls got a very early start to their murderous ways. Joffrey is an extreme version of spoiled, temperamental, and cruel. I don't know if he fits the mold of a psychopath. Likewise with Viserys. Viserys gets knocked but let's just appreciate what he was able to accomplish. He was penniless and had to take care of little Dany. He was smart enough and tough enough to survive and still take care of a child. He raised a fine young woman. For all of his faults, he was a very educated young man who passed it on to his sister. What he learned from the Maesters included a lot of rubbish but the important part is his accomplishments in teaching his sister how to read/speak in the Common Tongue and High Valyrian. Tywin, yes. Cersei, yes. Joffrey, I don't think so. Viserys, no.

He already ate Jojen. Bran's ready for his next human meal.

Arya will follow in Catelyn's footsteps. Her sole purpose now is inflicting violence on those she perceives to have wronged the Starks and any innocent people who might get in the way is just like swatting flies to her. Catelyn uses the Brotherhood as the instrument of her revenge. Arya is a lone wolf. She will use tools taught by the cult. Wildfire is surely on the table.

That Lysa is nuts is evident. Her son is underdeveloped emotionally, socially, and intellectually too. There could be an issue with little Lord Robert as well. Catelyn's sanity left her during her last moments as a living person. So yes, there are causes for concern and the presence of a gene which predisposes the Tullys to going nuts is worthy of concern that should not be ignored.

The three top characters, Tyrion, Jon, and Daenerys should not go insane. That removes agency and freedom of choice, and thus responsibility and culpability. But solely based on the premise of the subject, yes, if Jon is Targaryen then it stands to reason that his chances of going nuts is the same or more.

The variance is noted. HBO wanted to scratch the itch of the Stark fanbase who were screaming for Frey blood. I did not like the show and cancelled short of the last season. Arya is not sympathetic though. They are both right in that regard.

This bloody trail of her own making is not going to take Arya to a happy place. "Revenge has its own scent and it is not sweet." (Lace, 1984)