This character is already voiced in-game, so it's preferable if you can match the performance of one of her voice actresses to the best of your ability. As for the character herself, she is very reserved, determined, and headstrong. She is very dry and task-oriented. In this particular story, she is focused on trying to reverse engineer a piece of technology she hasn't seen before (Long story short, she is basically living in a "Ground hog's Day" type loop, so for her, she has seen a lot of different timelines.) When she discovered this piece of technology, she encountered a ghost named Tokki, Ghosts being companions for the players in-game. Tokki also had part of the foreign technology on her shell, the technology known as "silver". 

I've also included reference videos for the two different voice actresses that have played this character, so if you're interested, you can get a frame of reference for how she sounds. Basically anywhere between these two performances is what I'm hopeful for.

Reference 1

Reference 2