The real mystery in regard to Ultimecia's accent is why everytime she uses a sharp "c" sound she substitutes it with a "k" except when speaking of Time Compression:

"...SeeD..."

"SeeD......SeeD......"

"SeeD, SeeD, SeeD!"

"Kurse all SeeDs."

"Swarming like lokusts akross generations. You disgust me."

"The world was on the brink of that ever-elusive 'time-compression'."