Erza Scarlet is a S-class mage of the Fairy Tail Guild, the strongest still active female, and one of the main female protagonists in Team Natsu.
Erza, is a tall, beautiful young woman with long red hair, and brown eyes. She is almost always wearing an armored suit, made by Heart Kreuz. However, thanks to her requip magic, she can wear many magic armors, and can even requip swim suits, and clothes for recreational purposes. Her member stamp is on her left shoulder. She wears a standard medieval armor, but has a number of other themed armors such as Flame (or Lightning) Empress, which absorb the respected magic type, Adamantium, Samurai-style and more.
Erza is a very strict person, often criticizing the bad behavior and habits of the other guild members, causing most them to apologize for fear that they might invoke her wrath. She is also impatient, liking people who answer her questions quickly as seen when she promptly knocks out anyone who doesn't answer her questions (despite them not knowing anything). Also, Erza has a problem where she apparently sees everyone as guild members (best seen when she asks civilians to take things places during a mission). However, she has a great sense of justice. Despite being a very strict person, she seems to have a clumsy side to her as seen during the Galuna arc when she fell into a pit hole.
Like most Fairy Tail members, she shows great loyalty and dedication to Makarov and the guild. She pushed herself past her limit in the war against the Phantom Lord Guild, fighting against its many powerful members. She also became the temporary leader when Makarov had to be treated because of his scattered magic.
Although it hasn't been fully explored, it is implied that Natsu Dragneel, Erza and Gray Fullbuster are all very close to each other. While staying over at Lucy's house, Erza revealed that the three of them used to take showers together. It is later revealed that Erza, Natsu, and Gray have all been part of Fairy Tail ever since they were children.