Origin: Mediterranean - Half-human, half-bird fairies of Greek myth. They live on isolated islands and charm passing sailors into wrecking their ships. They were turned to stone by the famed lyre player Orpheus on the Argo expedition.
海に現れ 美しい声で うたうセイレイ 船乗りたちを ゆうわくして 船をしずませるTranslation: A spirit that emerges in the ocean and sings with a beautiful voice, seducing sailors and sinking their ships.
うみにあらわれ うつくしいこえで うたうセイレイ ふなのりたちを ゆうわくして ふねをしずませるTranslation: A spirit that emerges in the ocean and sings with a beautiful voice, seducing sailors and sinking their ships.
Siren is found in the Watchtower in the Factory, where she sadly sings, enthralling those living within. According to rumors at bars around the area, she was kidnapped from the Expanse by Holy Knights to use in order to brainwash the citizens of the Factory into mindlessly working without care for pay or their inhumane treatment. The rumors also say she is not singing to harm those within, but to mourn the loss of the one she loves.
Once Aleph finds her lover Petersen within Tiferet and brings him to the watchtower, she is reunited with him and finally stops singing. Together, they return to the Expanse, freeing the people of the Factory.