Como o @KyloRen o coloca muito bem na SciFi, vou apenas citar sua resposta aqui:
We finally have conformation.
Syrio Forel is dead and is not Jaqen H'ghar
I was really diapointed to hear this, but we finally have confirmation that he is neither Jaqen H'ghar or still alive. Showrunners David Benioff and D.B. Weiss have confirmed this.
"I always was like, 'Oh, no, I feel like he's still alive,'" Williams told IGN. "I always had my own theory that he and Jaqen [the Faceless Man] were the same person." But when she finally ran the idea by showrunners David Benioff and D.B. Weiss, they shot it down without hesitation: Forel is dead. "I was like, 'Oh, OK," Williams said, laughing. "So that put that to bed really quickly, but I guess we can all still dream."
Syrio Forel vivo ou morto? gamerones dos Game of Thrones finalmente dão uma resposta definitiva