Siddham Alphabet

Siddhaṃ script, also known in its later evolved form as Siddhamātṛkā, is a medieval  Brahmic  11000–1104D abugida, derived from the Gupta script and ancestral to the Assamese alphabets, Bengali alphabet and Maithili alphabet. It is an ancestor of the Devanagari script and several other Asian writing systems. Now it is used in Japan only where it is known as 梵字 (bonji). In general, Siddhaṃ script is used for Buddhist mantras and in design. In other regions, it was replaced with other alphabets, for example, with Devanagari.