Agni Purana (Jyotisha Selections) · by Vyasa
Chapter 3 · Name Letters and Chakras
युद्धजयार्णवः (चक्राणि)
अकारान्तं यथा प्रोक्तम इ उ ए विदुस्तथा ।पुनश्चैवांशकान्वक्ष्ये वर्गाष्टकसुसंस्कृतान् ॥ ९ ॥
In the full Agni Purana this is chapter 132, verse 9.
As it was told for the a row, know the i, u and e rows the same way. Again I will tell the parts, set in order by the eight letter groups.
Simple meaning: The rows of the other vowels work like the first. Next come the eight letter groups.
देवा अकारवर्गे तु दैत्याः कवर्गमाश्रिताः ।
Each group of letters belongs to a kind of being: gods, Daityas, Nagas and Gandharvas.
तवर्गे ऋषयः प्रोक्ताः पवर्गे राक्षसाः स्मृताः ।
The next letter groups belong to sages, demons, goblins and humans.
देवेभ्यो बलिनो दैत्या दैत्येभ्यः पन्नगास्तथा ।
Each kind of being in the list is stronger than the one before. The sages are above the Gandharvas.