Joi

She is a doctor and automail engineer at Fort Briggs.

An expert in the cold's effect on the human body as well as in cold climate automail, she is vital to the continued health and well-being of the soldiers of Briggs, and by extension the fort itself. It is likely that she worked on the development of Buccaneer's Modified M1910 and Heavy Combat M1913-A limbs alongside Neil.

[FMA Wiki]