So far I am happy with these two the artwork could be taken to a higher standard in the future if necessary . However I like the dynamic these sisters bring to the story especially If indeed they are the true daughters of the Pale Witch another one of her disturbing experiments into dark occult magic.
Now I see them in their final design they remind me of the weird sisters from Gargoyles a cartoon series created back in 1994 by Disney they were of the children of Oberon and possessed immense magical power such as giving Demona and Makbeth immortality. I am planning on the witch perhaps possessing one of the sisters and turning her into a witch like her true mother.
This would create and interesting situation that Johna Astora has to deal with during the events of the story.

I wanted the aspect of symmetry happening between the sisters to invoke their otherworldly kinship and most importantly they be in some form of physical contact to help focus their power. This was inspired by Mas Y Menos two characters from the Teen Titans cartoon show, super fast twin brothers who need to remain in physical contact to access their super speed http://teentitans.wikia.com/wiki/M%C3%A1s_y_Menos

After sourcing some images of various wise women and oracles I started sketching some designs In the end I went with a style of medieval dress often worn by wealthy upper-classes.

The Twin sisters Helgha and Meldra were borne of an unknown mother who seduced the king and gave birth to them in a single night. This has led many to believe the twins are the offspring of the witch of Margaul forest.
Despite the fact the twins have been nothing but great and valuable assets to the settlement they are greatly mistrusted by the towns people and feared as being double agents of the witch. While this is not true the sisters are not beyond the corrupting power of the witch.
Time can only tell what will become of these sisters, will they stand steadfast in the face of purity or will they fall into darkness and corruption.

The sisters have no direct influence and are largely from my imagination they are however loosely derived from tales of immaculate conception and unnatural births such as the Solar messiahs including Jesus, Horus Krishna, Mithra and many others.