haha.i thought vessels were this: In the Uchinha Clan, the teams of ninja were called vessels, instead of calling them "squads" or just "teams". Now, Itatchi says in one of the earlier episodes that he is his own vessel, that he doesn't have a team, he is his own team. that was the way he wanted it to be. so when he says he wanted to test his vessel, he meant he was just testing his strength and what he's capable of.idk what Shahelia is referring to but that is what i believe a vessel is.   See 4 other replies

I don't speak Japanese (yet) so I can't offer a translation. But my interpretation is that vessel is sort of the self. That is, it's the body as well as the determination and every ability that goes into achieving a goal. It's what everyone else calls skill when they're talking about shinobi ability. In Sasuke's case it's catching up to and perhaps surpassing his brother. He went into the Chunin Exam determined to test himself to see if he is strong. Itatchi's goals are more...unclear. (I've watched the anime up to the current point in Shippuden and I'm still not sure _why_ he needed to test his vessel - please don't spoil it, manga readers!)If you know Spanish well then consider the word "poder" and how it literally translates to power as well as strength. It's everything that you are capable of, not just physically but mentally, emotionally and anything else at your disposal (according to Guy Sensei that includes luck). I think this "vessel" they keep talking about would carry all their "poder" but one can't be sure just what/how much that is until it's tested.   See 4 other replies