SIREN HISTORY
The Sirens are 3 woman named Aglope, Peisinoe, and Thelxiepeia. At the beginning of there story they are Persephone's handmaidens. But when Persephone was kidnapped by Haides (God of the Underworld), Demeter gave them wings to help in the search. Hera persuaded the Sirens to compete in a singing competition against the Muses. The Sirens lost and the Muses won so the Muses plucked out all the Sirens feathers and made a crown from them. In there rage, they lured men at sea to there death.
Before Odysseus sailed by the island that held the Sirens, he was told that if a ship passed the island successfully then the Sirens would die. So as Odysseus went by the island, the water became still because divinity stilled the waters. One of Odysseus's men, Orpheos, played his lyre to a fast moving song to drown there ears in competitive sounds. They also wore wax ear plugs.
Once Odysseus passed by; just like the Fates said, the Sirens jumped off a cliff to there death.
END OF SIREN HISTORY AND BEGINNING OF THE STORY CHALLENGE
But the three Fates weren't done with them yet, the Sirens will be reincarnated.
Emma had Henry at 18 and put him up for adoption. Regina adopted him. Regina still casts the curse that sent everyone from the Enchanted Forest to Storybrooke.
In New York at age 20, Emma was approached by two women that are saying they are Sirens and she is one to. The Fates gave Emma a destiny that will rival or exceeds Odysseus's and Heracles (Hercules, Roman) destiny.
The Fates have decided that the Sirens job is to kill people on the ships at sea but only the ones that are destined to die at sea.
Because the job of a Siren can be traumatizing, the Fates allow Poseidon (God of the sea) to grant them the ability to talk to the ocean so they have some guidance.
In the 8 years that follow, Emma becomes close to the ocean. Emma never had a mother so she comes to think the ocean as her mother. And the ocean comes to think Emma as her daughter.
At 28, Henry brings Emma to Storybrooke. Emma takes one glance at Regina and is smitten. Emma goes swimming down by the docks and tells the ocean about Regina and asks what she should do. And the ocean wants to meet her.
Emma still has her job as a Siren in Storybrooke. When the curse brakes, the rest of her destiny begins. As she is not only a Siren, a Savior, but also the one to reunite Persephone and Demeter. Once the curse brakes, the Sirens are given there wings back so they can look for Persephone again. The wings allow entrance to Haides (Hell). But to escape, they will need dark magic. That is where Regina comes in.
But before Emma can save Persephone, Emma and Regina fall into the Mad Hatters hat and they arrive in the Enchanted Forest. There trip in the Enchanted Forest is what helps build there relationship more.
Regina is Emma's soul mate which is why she doesn't become enthralled when Emma sings.
Regina and Emma go through many quests and trials. And the ocean remains Emma's constant as all the oceans are the same in each realm.