Spoilers for epilogue
I am not sure if I'll this will be included in the epilogue but while Nanda and Adi are at the battlefield and Vaishu is fighting the internal battles, Amma wrote a song.
She is always into making songs and this will be touched upon the prequel as well. As a matter of fact Nanda picked up this trait from her. Anyways, Amma, since she now knows how to write, actually writes the song.
Nanda finds it and he takes it to Adi who liked it so much that he orders for this song to be played during the upcoming court sessions for more and more people to hear it since it is that beautiful.
Later this also becomes the Army's official anthem as everyone loved it so much
Anyway this is the song
https://youtu.be/I4tBs4xipw8?si=5lM-mJ_m1nImwszx