City of Legends - City of Legends, #1

Maci Knight has grown up in the shadow of legends. Her father and her brother, Max, are Heroes, worshiped by humans and Supers alike for their strength and valor. All she's ever wanted is to follow in their footsteps, to fight villains and protect humankind. But Maci has a secret-one that could change everything. Maci had a twin sister who died the same day they were born. In their world, one twin is always good, while the other always eventually turns evil.
There's no way to tell which twin will go rogue .