Why there must be a " Cid " character in most of Final Fantasy projects ?

yesterday I was watching the cartoon series " Final Fantasy Unlimited "

and there was a Cid!

I said sh*t - can't they get enough of Cid.

not only that - there are about what? 4 or 5 Cids in FF projects??

well, if you wonder what characters are going to be in FF XIII and
FF XIII Ve. I'll tell you there will be a " Cid " at both games!!!!!!!