Souhou requires a big empty space and a bag of powdered crystal which is used to draw the circle. The purpose of the circle is to first contain and control the massive influx of energy user gathers when first preparing their attack. Its second function is to use the symbols and sigils within the circle as a means of regulating the flow and formulating it into the attack they are attempting to cast.
The circle is used to achieve the necessary train of thought and to contain the immeasurable energies user is calling upon. After they finish stands in the center of a crystalline design before forth their ki and thrusting it down into the circle, starting east in Zhen, the direction of excitation and the arousal of energies. From there they direct it southeast. The powder melts together into glass as the energies spin around user, growing more and more. Slowly the energy comes back around to meet itself in the circle. User then calls it back into themselves.
User acts as a conduit for the ki magnified by both the crystal and the circle allowing them to be better able to control the seemingly chaotic energies of and perform their attack with supreme ease. Unfortunately this technique is relatively new and unrefined and there are still a few design flaws, the main one being that, unless it's used carefully, it can cause quite a bit of collateral damage. Therefore it is extremely dangerous both to its victims and its user. Another flaw is that Souhou takes quite a bit of time to perform leaving the user vulnerable.
One of the greatest strengths of this technique is that the user need not utilize all of its energy when performing it, they can store and reserve it for later use, or transfigure another attack by rearranging the components to create entirely new effects. This allows for an incredible level of flexibility without the drawback of backfiring.