Gavinmad
Mr. Poopybutthole
Maybe, but I think Syrio is dead. I doubt Ser Meryn would have bothered taking him alive, and while normally GRRM doesn't hesitate to show people being killed, I think the reason he didn't show Syrio's death is because Arya, the POV character, fled the scene. Most of the Syrio=Jaqen theories revolve around the idea of Varys having needed to keep a faceless man around for a while, but that doesn't make much sense. Faceless Men don't seem like the type you hire on retainer, you contract them for a job and that's that.