This is very interesting Hades.
The triumvirate of 3 forces has always been a very sacred element in both spiritual and magical context.
In the vampyric community the balance of the triumvirate has been implemented in many societies where the highest representatives are the 3 pillars of the society often Regent (or Keeper of the Ceremony), Keeper of the Veil (Guardian) and Keeper of The Scroll (Scribe). The three Castes or Roads Kitra, Mradu and Ramkht are also part of a triumvirate.
Most, unfortunately, see the dichotomy of negative and positive forces as a parallel of good and evil, which it is not. Negative energy has a function just as important as Positive energy ... one des not preclude the other in fact one is only possible because of the other.
I believe that we have a bit of each polarity within us and much of the balancing neutral factor as well. How we balance it within us is in essence our twilight.