Dear all, let me outline the Ugra Prathinkara perfection in brief.
The austerities for the perfection is same as that of the shanta form but the mantra used will be mentioned in the ugra form of sadhana.
The added advantage of this perfection is, when this mantra becomes perfected, one will be able to send the evil spirits back to the place where it was being sent. This is one of the mantras commonly used for sorcery. I strictly advise not to do this. :)
similarly, when an yantra is written for prathinkara based on this mantra will be a great help for protection.