Actually I said, there can be only one UNLESS you can impress me so...if this person impresses me, then I will allow it. 
You didn't make this race, it exists in this world, it's just rare. No justification? I'm the GM, I can do whatever I want. If Ryse wants to play an immortal, and he or she impresses me, then he or she can play as an immortal. 
Please go on, I'd love to hear more.