The first is about the Arthurian character Sir
Kai:
I've seen his name spelled
Kai,
Kay, and Cei. I'm assuming it has also been spelled
Cai, Cay, Kei, etc. Is any one spelling "more" legit than the others? Which spelling is the oldest?
The second question is about the spelling "Keffyn". I've seen it on a real person before and was told it was Welsh. Is this spelling legit?