Akuma no Yuritani (Mizu twins)

Akuma no Yuritani. [Rough translation: Demons of Yuritani]
::STORY::
They’re the living truth of what people thought as folklore. A place among the serene mountains, in the edo era, was rumored to have demons. Kori and Yumi are the ones who seduce, enthrall and sacrifice humans to sate their bloodlust. Their soul purpose is to kill as many as possible without detection. The souls that are banished by their hands become the food of their beloved demon lord, Onikage. As humans are becoming more and more familiar with the killings, the Mizu twins have no choice but to continue changing places, usually seen in forest swamps, or near the hot springs that are deserted because of the vile aura surrounding them. Even so, they manage to slay one or two souls every month. Aside from that, they hate being bothered by demon-slayers, priests and shamans. Though they don’t mind working for other demons, who promise them ‘Virgin Tears’ the secret to their youthful beauty.
::VITAL STATS::
Blue sash twin: Kori Mizu [Rough translation : Ice water]
Green sash twin: Yumi Mizu [Rough translation : Dark water]
Race : Water demons.
Hair: Black.
Eyes: Green/Violet.
Height: Depends on the formation of body.
Weight: Unknown. [AN : How can you measure water? To the physics lab!!!.]
Physique: Unknown. [AN : You have got to be kidding me. >.> Just uh, think of your perfect girl figure. X3!]
Skin Tone: Pale.
Occupation: (none really, they belong to the swamps or forbidden places and hope to catch a human.) Devouring souls, eating humans, flirting to death?. [AN : I wish I had one of these as my servants. e.e]
Weapons: They themselves are the best weapon, one could think of.