There are Kabbalists that see against the energetic brightness of the holiness of the ten heavenly spheres that are up in the nobility world, a ten levels system of impurity below, that is called in the "Zohar"- "Lower Crowns" (in Aramith: "Ktarin Tate'ean"), the "Lower Crowns" are the nether stairs (in Aramith:"Dargin Tate'ean"). That is to say, that against the picture of the ten positive light demensions there is a negative of negative black.
Against the crown sphere which is the White Head there is Satan, the "Sitra Ahra", he is the Black Head also called Lavan Ha'arami. Against the holy image of the ancient man there is a cosmic system in the image of "Belial" man (belial is something like vandalist in Hebrew) that is in charge on the powers of the "Sitra Ahra" and strives to unsettle the balance of the creation to the side of the negative energy that is in the powers of law, evil and impurity.
If in the space of the universe the crown sphere gives birth to new systems and gives them life and serves as a white hole that creats worlds, than the kingdom of the "Sitra Ahra" has black holes that suck into them in multiple dimension cosmic vortex, things of the creation and even consumes whole galaxies and transfers them to the Black world.
In another perspective, the "Sitra Ahra" is a positive servant to the cosmic order. Since the Crown sphere symols the "tree of knowledge good and evil", the positive and negative, the plus and minus that is in it, it can represent in the cosmos in both times the two powers and harnesses them to the divine plan. The gate, or the black hole, is being used as a tunnle between the different time dimensions that absorbs energies, swallows them and transfers them to another time dimension, to the spheres world and in the same time as a white hole (that in the other side of the black hole) the same tunnle ejects and creats galaxies from the energy that abounds from the spheres that in the "Nobility world".
The black formation that apparently stands against the ten spheres, is not negative in the valuel meaning but is used as a shadow of the spheres, as the facest that balances and completes in the infinite formation of decimal bunches of spheres, that also sucks its living from the holiness from the spheres in the "Nobility world".
There are Kabbalists that look in the demical formation of the dark powers as the "peels" that wraps the spheres in love, like the hard and bitter peel of the fruite was intended to protect the content and the juiciness of the fruite, like the hard scalp that protects the brain. The cover of the dark forces is used as a kind of atmospheric covering of energy that prevents from external factors that are not qualified in their inner balance for the travel from aprouching the spheres, In order to prevent them from making the first man mistake and will cause a cosmic accident of blocking the tunnles between the spheres. These "peels" are also intended as "clothes", to hide and shelve the abundance of the divine light and to supervise the amount of its radiation, to make life posible in the lower dimensions of the universe. That is how a natural scale in the construction of the different worlds. The Sitra Ahra controls this task in the book of Zohar, the same guardian snake, as a loyal emissary or as a slave, of the holy treasures of God and subjected to his total mastery, and only the Angels, Kabbalists or Righteous knows how to keep it away in order to get close to the energetic treasures that stashes in the Crown sphere.
By this approach prevails a harmony and completion between good and evil, because the acts of evil apperantly, have positive purposes of fulfillment the divine destiny and they are used as frightning dogs that guards with their lives on the entrance to the house, and when the sign is given they become soft and submissive pets.