The mantras notify its emergence during the age of dark faith i.e. before to the emergence of Vaishnavism in the 15th century. The most popular of these mantra puthis are: Karati puthi, Virajara puthi, Sapara dharani mantra, Sarvadhaka mantra, Suci mantra, Mohini mantra, etc. Some of these mantras of the primitive period have Buddhistic impact on them. The mantra literature based on belief in superstitions has evolved out of the crude practices of primitive magic and Sakta tantrism. They are practiced in harmony with the mysterious forces of Buddhism.
The writing style of the play is devoid of grammatical perfection. Words were set in a formal structure to convey the magic purposes of the mantras in a logical way. Every word used is supposed to have a certain power of magic, and stimulate magical effects required. Words such as Om, ain, hrin, srin, etc., used in mantras are magical symbols without any rational meaning. The word Om was possibly used to spiritualize mantras with a Vedic veneer. Even the Vedas have mantras pertaining to Atharva Veda. Mantras are mostly esoteric in nature. For example the Sanskrit mantras, the Upanishads, the Buddhist literature and the Vedic texts appear to be incoherent and peculiar in nature. This is because in keeping with the spirit of the mantras, the language had to be aptly modulated so that it is capable of adding mystery to the world of magic. The mantra pithis contain mantras of descriptive nature like the Sudarsana karati: these are a milestone in the historical development of old Assamese prose literature. The following example is a depiction of Lord Brahma's court in Sudarsana karati:
Brahmadeva bahi ache camatkara Kari.
Thus, it goes on to describe Brahma in the company of other gods like Lord Indra, Kuvera, and Lord Varuna. There is also description of spirits in contrast to the heavenly gods: karo eko khana kana kulara samana, spirits with ears as big as a winnowing fan.
The play through its sequential sentence framing has a rhythm and even provides considerable emancipation of thought. The play is a significant milestone in the history of early Assamese prose. The carita puthis, whether in prose or in verse, are a bold experiment in the art of biography. The ultimate purpose of these biographies penned down by the followers of Vaishnava saints like Sankardeva and Madhav-deva in particular was to create a religious impact by highlighting of the lives of saints. These biographies are noteworthy from the point of history because they bring into notice the life and doings of the saints in a reverential spirit and also focus on the socio-religious and political sanctions of the time. The carita puthis are mainly colourful versions of the lives of saints significant for its contribution to the evolution of old Assamese prose.
Another significant biography is the Bardowa Gurucarita. The 17th and the 18th centuries comprise of the zenith of carita puthi literature and buranji prose. The first biography to be written in Assamese was Sankara carita by Ramacharana Thakura. Other biographies are Sankardeo-Madhavdeo by Daityari Thakura, Sankara carita by Bhusan Dwija. Apart from these carita puthis of other personalities of the Vaishnava movement like Gopala Ata, Damodardeva and a few others were also written.
The carita puthis seek to simplify the Assamese prose with emotion and lucidity. In carita puthis the conversations and descriptions are consistent and interconnected. This provides an elegance and sophistication to the prose. The structuring and framing of the sentences, the usage of simplified words coupled with clarity of expression are an absorbing evidence of early Assamese prose in its evolutionary process. The language used in carita puthis is a chiselled synthesis of words spoken in eastern and western Assam. The carita puthis are written in the monastic tradition, whether in verse or prose.