Like Kaya said. It's one of the rules. One of the main ones, and what makes the roleplay senario work. Having two of any elemental would render the senario moot, and it would cause one to become more powerful than another.
As a reminder in case of this coming up, no to any new powers. Period. There are absolutely no exceptions except mind powers, and that must be used carefully. Reading minds must be at the permission of the roleplayer in charge of the character you want to read the mind of, and no telekinesis. Mind control must, again, have permission of the roleplayer. Above all, everything must fit with the current rules. Get to know them. I'm tired of having to tell people not to Powerplay, Godmod, or any other rule. The way I asked it formatted is a lost cause at this point. I figured that out already.