Celestine is a unique and rare variant who can safely wield multiple essence. This variant has no physical difference. They are not heritable and can only be gained by a baseliner, as far as record goes.
Unlike other, they can manipulate more than one essence simultaneously without the risk of self-overloading. They are, however, locked to generating fire essence. Because of it, every Celestine in history are fire adept despite the elemental flexibility.