NHF – new heroes for Heroes V 3.1.

Here is my IMHO:

As I understand it, there were two sisters at first – Kate and Deidra, then Kate passed away, and Deidra, taking advantage of the situation, took her place, naturally calling herself Kate, and later became a servant of Malassa "...In her wanderings, she experienced much and found her inner Dragon, ultimately deciding to become a Knight in the service of Malassa, the Dragon of Darkness..."
Deidra the Necromancer is a completely different character.http://ru.ashan.wikia.com/wiki/%D0%94%D0%B5%D0%B9%D0%B4%D1%80%D0%B0

Therefore:
1) Deidra the Necromancer should not be touched.
2) Kate (the real one, who was killed during the war with Tuidhanna), if added, would be better as a Knight.
3) Kate-Deidra (Deidra, who, after her sister's death, called herself by her sister's name – Kate), if added, should be in Dungeon – she did become a dragon knight of Malassa after all. http://ru.ashan.wikia.com/wiki/%D0%9A%D0%B5%D0%B9%D1%82