Sailor Mercury is the second Scout to join the team. She is the brains of the operation, using her hand-held computer to track enemy movements and scan areas for traps. Unlike Sailor Jupiter, Mercury will think things out rather than duke it out. Sailor Mercury's attacks consist of water and are almost exclusively used to disorient or paralyze opponents. Ironically, Luna and Serena initially thought that Amy was from the Negaverse. That theory was rejected when the sign of Mercury appeared on Amy's forehead when she was attacked by one of Jadeite's minions. Amy discovers a new student named Greg to be her intellectual equal and they get to know each other really well. It is later revealed that Greg has clairvoyant powers since he is one of the carriers of the seven Rainbow Crystals. Practical-minded as he is, Greg begs Sailor Mercury to destroy him when he turns into a monster, but she makes him realize that he is in control of his own destiny and not powerless in the hands of fate.
Unlike the other four Scouts, Sailor Mercury's powers are used primarily for defense. In combat, she will often be the first Scout to use her powers, blinding or freezing the enemy which gives the other Scouts the opportunity to attack. Like Mina, Amy seldom gets angry and shows genuine care for her friends, though often she will forego outings with them in order to study. In one episode she frets about only being ten chapters ahead in math and worries that she'll only get an A- on the math final. Needless to say, the others groaned. It is rather amusing to watch Amy deny the fact that she has feelings for Greg, saying that she has too much schoolwork to engage in a relationship. Finally, Lita says to her, "Ever heard of that river in Egypt, De-Nial?" and she confesses. Sailor Buben and I are particularly fascinated by the fact that Sailor Mercury will accentuate the last word of the attack she's using: "BLAAAAST", "FREEEEZE", and our favorite, "Shine Aqua ILLUUUUSION!"