Waves of Change
Echo and several of her comrades joined Captain Striker in visiting the Eusebes Shrine, where they were angered to discover Sonic the Hedgehog, Amy Rose, and Rotor Walrus. Given that the trio were guests of Priestess Coral the Beta, who had not received permission from King Puff and Queen Angelica to have them at the shrine, Echo was left to guard the shrine while Coral and the others were taken before the royal family. Later, she led a force of guardsmen back to the shrine in order to help fight off Dark Gaia's Minions. (StH: #260, #261, #263)
Search for the Princess
When Princess Undina went missing during her studies in Spagonia, a ransom was sent demanding money for Undina's return. When no one appeared to retrieve the ransom, Echo was assigned by the King and Queen to search for Undina. Her first action was to interrogate Professor Pickle at Spagonia University on Undina's whereabouts, who mentioned to her that Undina had departed to Empire City. There, Echo discovered Undina had briefly partnered with Honey the Cat to advertise Honey's fashion line. Echo learned from Honey that Undina had decided to embark on a world tour. After receiving information from an anonymous source, Echo learned that the princess was last spotted somewhere in Westopolis and the ransom demand came from pirates. However, Echo's lack of familiarity with the city led her to requesting the Chaotix Detective Agency to assist her in finding information at the docks.
With help from Vector, a dock worker named Daryl admitted that he saw Undina with the Pirates heading toward an island called "The Knives". Echo and the Chaotix decide to head to the island with Echo's submarine-convertible car. During the trip however, they run into an unknown construct. Supplying the Chaotix with air charms, the group checked outside and were ambushed by Razor the Shark and his chao Crusher. Espio ceased the hostility between the two parties, and Razor revealed that he was also trying to find Undina and the pirates on Coral's behalf. Echo then noticed how odd it was that they ran into Razor where the pirates were, and questioned how Razor also knew about the pirates' involvement. Before she could confirm her suspicions, the pirates' nearby ship caught the group in a cage. The group was then dumped onboard the ship, and the group found themselves confronted by the pirates, Undina among them. (SU: #91)
Echo is very dutiful and dedicated, though maybe to the point of being slightly uptight. She also takes her job very seriously as she followed and upheld Striker's orders without question. She seems to also consider Striker's views on others, as she questioned if Razor's activities supposedly validated Striker's suspicions on him. However, she does not do too well out of her element, and has trouble understanding surface customs.
When on her own assignment, Echo maintains her commitment, although her focus on her objective leads her to extreme lengths to complete it, no matter the payment. She is quite determined and considerate of every detail in her work, looking into all the information she could find and preparing for the scenarios she came across. Her sense of duty can lead to moments of worry and uncertainty however, and she can feel strong concern for the safety of the royal family.
Powers and abilities
Echo is capable of aquatic respiration, allowing her to breath both on land and underwater, as indicated by her dwelling in Meropis without the apparent use of an air charm. Echo carries a trident which is a standard weapon for the City Guard. In addition to being useful for melee combat, this weapon can shoot out a thin laser from its points.
Echo is a humanoid dolphin of average height. She has purple skin and a white muzzle with a rounded shout and purple dots on her chins which resemble freckles. She has a dorsal fin on the top of her head, the back of her head and her regular back, a caudal fin as tail and has no toes or nostrils. As attire, she wears the standard City Guard uniform which include black shirts and shorts, green additional garments and a golden helmet adorned with shells. She also wears a shell bracelet around her right ankle.
- Echo's name is likely a nod to Sega's Ecco the Dolphin series of video games published by Sega, though the dolphin protagonist Ecco is a male, non-anthropomorphic dolphin.