makkun said: So, what is her role in the story exactly?
None. Patroklos and Pyyrha are the primary focus. Everyone else just kinda helps Patroklos, but they don't have any arc of their own.
Worst of all, ZWEI's death was completely padded in without revealing any of his story and that he before he fell off a cliff, he seemed to know Tira. That's the only piece of story you'll get from any character besides Pat and Pyrrha.