(If you want to go directly to summoning an entity to aid you - skip this section and go directly to section 13 onwards).
Chudarmanian was a High Aaiyyani Priest who formulated and took part in the Kalaiyyan incident. She was also said to be the close partner (or even wife) of Lavalian Gatisaman. After the Kalaiyyan massacre in which they too were also killed, it was said that Chudarmanian was sent to the Bhoot Tala (realm) as a Karmic punishment from Brahman. (Though some Tantric Aaiyyanists say that is was by choice and Adhavena wished to be in the Bhoot realm to exist 'separately and together' as is the Kalaiyyan Tantric tradition).
As per Lavalian Gatisaman, Chudarmanian formulated the Aaiyyanist Dravidian symbolic scriptural magic required to open the Bhoot Tala. Chudarmanian was a very skilled researcher into the Dravidian Aaiyyanist scripts passed from Siva to Murugan to open the portals between Lokas, Talas and this realm to facilitate links from man, spirit, entities, Gods to Brahman. She devised and scripted the formula required to open the Bhoot Tala so that she could converse with her followers which includes your previous self. Yes, the fact that you are reading this now means that in your previous incarnation you were a follower of Gatisaman and Adhavena.
Aaiyyanists believe that there are no coincidences and the people you meet in this life... you have already met previously in your past lives. You are basically just fulfilling Brahman's Karmic laws. Likewise the Pretas, Bhoots, Pishachas, Asuras etc... that you will meet in this life when you use the knowledge in this book, you have already interacted with in your previous infinite incarnations. We are not just talking about the incarnations in this Universe's lifetime, but the many Universes that have existed in the past and future.
Chudarmanian's Tala inscription can be found above, and in section 14 where there are more details on the summoning ritual.