Echo

"Leo: "Blue Elephants." Echo:Blue Elephants." Leo: "Kiss me, you fool." Echo: "You fool." Leo: "Hey!""

- Leo teasing Echo

Echo was an Oread (a mountain nymph) who loved her own voice. However, for aiding Zeus in consorting with beautiful nymphs, Hera cursed her to only being able to repeat the words of other.

History
Echo was a young and beautiful nymph that would sometimes help Zeus when he came down from Olympus. While Zeus was off flirting and consorting with other nymphs, Echo would tell stories or songs to his wife Hera to distract her. Eventually, Hera discovered the trickery and cursed Echo to only ever be able to repeat the words of others.

Eventually, Echo saw a man named Narcissus hunting in the woods and followed him, hoping he would introduce himself so she could talk back to him. When One day when Narcissus was out hunting stags, Echo stealthily followed the handsome youth through the woods longing to address him but unable to speak first. When Narcissus realized he was being followed he called out "Who's there?"

Being forced to repeat him, she called back the same question which only served to confuse Narcissus. Still unable to see her, he asked why she was running from him, to which she replied with the same question. Finally he says "Let us meet together." Echo repeated the words enthusiastically, running from the woods and wrapping his hands into her own. However, Narcissus ran away from her claiming "May I die before what’s mine is yours." Echo only repeated "what's mine is yours."

Later, Echo found Narcissus looking at his reflection in a pond. Narcissus, who had fallen in love with his own reflection as punishment for breaking the hearts of so many girls by Nemesis, would talk to his reflection and say how much he loved it. Echo, who would watch Narcissus would repeat everything Narcissus said to his reflection. He eventually died however when he drowned in the small lake.

Echo died when she refused the advances of the god Pan, who had fallen in love with her. As punishment, Pan caused a panic, causing the people in the area to kill Echo and scatter her all over the land. Gaea collected the pieces and made it so Echo could be heard all over the world.

The Mark of Athena
Echo appears when Hazel Levesque and Leo Valdez go looking for Celestial Bronze and lime on a small island. After Leo tried to figure out who the cursed boy Nemesis mentioned was, he heard a girl repeat what he said, but couldn't see her. However, he was able to eventually find her after his eye's adjusted. The girl was forced to repeat everything Leo and Hazel asked, leading them to the conclusion that she was Echo, another soul that had escaped the Underworld using the Doors of Death. Leo at first teases her a bit, trying to get her to say funny things, but she quickly turns it around on him and Hazel yells at Leo to stop teasing her when he gets mad. She is able to ask Hazel and Leo for help and leads them to the lake where Narcissus is. On they way, they kept losing her as she would mirror any background she walked in front of, causing her to constantly appear camouflaged.

When they make it to the small pound, they find Narcissus sitting on the shore looking at himself in a Celestial Bronze shield, which Leo needed to fix the Argo II. However, the nymphs in the area also love to stare at Narcissus and become very aggressive at Echo, saying she already had her chance and is not good enough for him. While Echo only wants to make Narcissus stop looking at himself to prevent him from dying like he did during his first life, doing so would make the other nymphs upset as Narcissus wouldn't stay by the pond anymore.

In order to save Narcissus and get the bronze shield, Echo helps Leo in his plan to distract Narcissus long enough for Hazel to get the shield from the water. Leo gets a makeover and proceeds to return to the pond, making a big show of it and calling Narcissus weak. Echo repeated all of Leo's words, but because few could see her, some nymphs thought it was nymphs in their group instead of Echo. When Narcissus becomes so annoyed that he turned away from the bronze, Hazel pulled it from the pond and ran with it. Narcissus quickly figured out the trick and ordered the nymphs to get the shield back, which Echo unwillingly repeated. While running away and waiting for Arion to pick them up, both Hazel and Echo stood in front of Leo to protect the shield. This surprises Leo and he complimented her. He also tried to get her to forget about Narcissus and come with him instead. However, when Arion arrived, Echo told them to leave her behind, as she still hoped to one day save Narcissus. Before he left, Echo kissed Leo on the cheek and he could see her real face for just a moment. He to himself that he would never forget what her face really looked like, but found that the memory was slipping away only moments later.

Personality
Despite originally being punished for being a gossip and helping Zeus, Echo is very humble. She is deeply in love with Narcissus and hopes that she will be able to save him, despite the interests of the other nymphs. Despite Narcissus not caring at all for her, she is completely devoted to him and tries her best to help. When Leo aids her by stealing the shield he was using as a mirror, Echo stood against a large number of other nymphs to aid in Leo's escape, showing that she isn't afraid to put her life in danger as long as it helps Narcissus. Despite Narcissus not caring at all for her, Leo is able to see just how good of a person she is.

Appearance
Echo is a young girl. She wears a Greek-style tunic which changes color depending on the surface she is standing in front of. Because of her curse, Echo appears almost invisible, as her body will mirror any background she is standing in front of. When she was standing in a field, her hair appeared wispy and looked like a mixture of brown, blonde, and gray to match with the dried grass around her. When Leo looked at her face, he mentioned that is was pretty, but not memorable and found himself having a hard time actually remembering what it looked like. However, when she kissed him later, he could see her face clearly and marveled at her blue eyes.

Abilities
Because of her curse, Echo can only say the last thing she hears others say, but can't say anything on her own. However, the curse also allows her to hide very easily as her body will blend into whatever she is standing on or in front of.

Trivia

 * Echo is the first person (besides Hazel) to be revived using the Doors of Death, but does not work for Gaea in some way.