Both Naphele and Themis are the twin daughters (also immortals) of Gaya Titania Gei and The Life King (2nd incarnation - Prince Zaselim Raz).

Home World: Novenary, on the 4th Sky/Plane, The home of all Norse.

They are also helping Gaya in searching for their father, Prince Zaselim, after he went missing during the events of invasion in the world Novenary (World of the all Norse Gods and 9 realms). 

He was 20 years old at the time and the girls were 2. No one knows what happened to him or where did he disappear to, and they are searching for him just like Penthesilea Z. (their eldest sibling born from Gaya and Zi'Ayt Chronus, the first incarnation of Life King and the (failed experiment) 8th clone of Zeus Chronus) separately in different worlds/places and then tens of thousands of years later one day they meet Zesiro Zuka, a 14 years old (ran away) prisoner kid with white hairs and blue eyes, on the 6th world called "KERMET"(world of the Egyptian Gods) also known as the world of Sands, who is hated by almost everyone as the spawn of the Devil. 

And their adventure begins. 

Naphele Z.

Skin Complexion : White.
Hairs: Long, Blue.

Height: 5.11 ft.
Eyes: Greenish Blue.

Special Power/s: Holds the power over water.

Themis Z.

Skin Complexion: Fair (a bit darker than Naphele).

Hairs: Shoulder Length, Bluish Grey (a mixture of both Life King(white) and Gaya's(blue) hair color).

Height: 5.11 ft.

Eyes: Greenish Blue.

Special Power/s: Holds the power over ICE(Frost).
 

Like some of the immortals and they don't have their own Dragos but they draw power from High Level Dragos, Naphele and Themis doesn't have their Dragos but instead they draw their from the same source (unknown Dragos, some think Its not hatched/born yet or lost somewhere) same as some of the high immortals Poseiden and Ageir . Naphele has the power over waters and Themis over everything Ice(even snow).

Legends say that they rivals the strength of high immortals and even more than them, immortals like Poseisden(Greek Mythology) and Ageir(Norse Mythology).

They also cancel out each other in terms of power as their power source is the same and therefore they can't hurt each other with their power.