Sailor Mars would begin Fire Soul by clasping her hands together with two index fingers pointing outwards (the first "kuji" gesture). A fireball would form at the tips of her index fingers which she then shot forward, killing or wounding her enemy by engulfing him or her in flames.
Sometimes Sailor Mars would combine Fire Soul with another Senshi's attack, such as in episodes 11 and 24, where it was combined with Sailor Moon's Moon Tiara Action; episode 21, where it was combined with both Sailor Moon's Moon Tiara Action and Sailor Mercury's Sabão Spray; in episode 36, where it was combined with Sailor Jupiter's Supreme Thunder; and in episode 48, where it was combined with Sailor Venus's Crescent Beam.
Fire Soul appeared in the musical Pretty Soldier Sailor Moon ~ New/Transformation - The Path to Become the Super Warrior - Overture of Last Dracul.
Hi is the character for fire, which Sailor Mars' powers are based upon. Rei means "soul" or "spirit", but is written in katakana (which is commonly used for foreign words) to show Rei's exotic nature. Once again the -no shows possession, and Rei's name means "soul of fire". Since ancient times, the planet Mars has been associated with fire because of its bright red color.
Fire seems to symbolize purification and rebirth both physically or spiritually in many cultures and can also be seen as a living entity through which wisdom can be gained. For example, compare Rei's firereading to Moses' burning bush and the famous writing on the wall in the Christian Bible.
Fire can also be seen to represent destruction and chaos or even war, correlating closely with the God of War, Mars (Ares in Greek mythology). Fire appears to have even greater meaning for the character of Sailor Mars.
- In the Dic English dub, During her first fight with Catzi (Koan), Sailor Mars says "Mars Fire Star Flash" before they clash each other with their fire powers.
- Her first ability becomes weaker when Koan manages to extinguish it with her dark fire, only to be repelled by her second ability, Burning Mandala.