Firefly is sweet, soft-spoken and a little shy. But she is extremely intelligent due to her genetic modifications. While she may look soft-spoken, she can be fierce and almost merciless in battle as SAM. Whenever she transforms into SAM, she puts on a stern and boyish facade since SAM sounds like a boy due to the voice changer within the armor.
Firefly is usually sent into battle when the Stellaron Hunters face a formidable enemy. But, she independently joins the battlefield sometimes.