The Strongest Vampire

Tasha and Stella Garcia were one of the first vampires ever created. They are twins and are believed to be a myth. Vampires classify them higher than the Voltori!
Tasha is a Mirror. Any vampire that has a gift, she can "reflect" it. She can retain the power and use it whenever. She is untraceable. That's why vampires believe that there a myth... No one has prof!
Stella on the other hand has no gift. If it wasn't for Tasha, they would have found her already. That's why they stick together.
When the twins hear that the Voltori is fighting against the Cullen's because they believe that the Cullen's have created an immortal child, they come out of hiding to witness if what they say is true. But the question is, is it worth it?