Just trying to figure the lore out behind this brat. 
So his name is 'Shieda Kayn', with Shieda being Ionian and Kayn sounding... not. So did Zed name Kayn when he was a kiddo? Did he have a Noxian name before hand? Or was he already called Kayn and Zed was like 'here have a first name even if I don't have one'.
Im 
ed trying to keep up with all the new Ionian lore, LOL.
Kayn was a Noxian child soldier who survived a lost battle, and was taken under Zed's wing in the Order of Shadows, roughly. Not sure exactly where Kayn came from; perhaps its the only name he called himself, and presumably Zed named him Shieda.
As we've seen in Zed's comic, being given new names as honorifics is a thing they do there. It's entirely possible that at least "Shieda" is a name that Zed gave to him when he became Zed's pupil.
I'm guessing Kayn is his Noxian name; it seems like very poor Noxians, such as Riven and Talon, seem not to have last names (Talon currently takes on DeCouteau as his last name, but that's only by adoption). Thus, as Honest John suggested above, Shieda is likely an honorific or a praenomen that Zed gave him honorarily.
Yeah, I'm pretty sure it wasmentioned in the AMA that Shieda Kayn is not his birth name but the name he took after he becomes a part of Zed's order. However, I'm currently not able to find the exact statement.
