At some point, their mother died, and their father took it hard. Neritos kept their family fed by fishing. One day, Neritos washed out into the sea, and believed himself to be doomed to drown. Somehow, however, he crawled out from the ocean floor and made his way back to home, where he found his father dead and his brother sold into slavery. 
Losing faith and trust into the gods he used to worship, and having lost his family, he set out to create a new one, and named the gang The Dagger. The name Neritos he left behind, preferring to go by the cryptonym 'The Kingfisher'.
During the Peloponnesian War
By the Peloponnesian War, the Dagger had done their best to claim Euboea and Skyros, with Neritos hiding in the shadows for the previous decades. Despite this preference for hiding, his reputation preceded him, deeming him to be cruel and driven by greed. He also made a habit of visiting a local farmer, dining and staying at his farm in the Dirfi Foothills.
During the war, the local magistrate whose slave Agapios was, decided to uncover the reach of the Dagger's operations, as well as their leader. They drew the attention of the Spartan misthios Kassandra to the matter as well, as she was passing through Chalkis City.
Following Agapios' clues, Kassandra found out that the leader of the Dagger was Neritos. They faced him at the Temple of Achilles on Skyros. Neritos attempted to talk Agapios into joining him and the Dagger, while the magistrate and Kassandra expressed their own opinions. Ultimately, however, Kassandra killed Neritos, as well as the leadership of the Dagger, gathered at the temple.
Behind the Scenes
In Greek mythology, the kingfisher was born from a couple that died at see becoming a symbol for resurrection or renewal and protection at sea but also for peaceful days now past.