The Blood Energy circulation, Materialization Technique, Blood Plundering Technique, and the Soul Dismantling Spell were the names of the four forbidden techniques.
The Blood Energy Circulation dealt with utilising the blood energy of the user.
The Materialization Technique enabled powerless humans to be able to draw the mystical energy within unique materials for their own use.
The Blood Plundering Technique was a modified version of the Blood Energy circulation, but it relied on alternative sources of blood energy apart from the user.
As for the Soul Dismantling Spell, it was a forbidden spell that could be used to absorb and decompose souls to form soul energy, an artificial mystical energy.
Big discounts in privilege. Check auxiliary chapt for more info.