Concept art
Rei's Soldier identity is Sailor Mars. She wears a sailor suit colored in red and purple, along with red high heels, and in the manga and live-action series has a small red jewel at the waist, though this vanishes upon upgrades. (Concept art shows this was supposed to appear as a necklace when not transformed but never does) She is given specific titles throughout the various series, including Soldier of War and Guardian of Flame and Passion. Her personality is no different from when she is a civilian, although certain powers are unavailable to her in that form.