There is an interesting story in the Datta Purana related to Kartavirya Arjuna. This katha (story) connects the birth of Karthaveeryarjuna to Sudarshana Chakra.
Kritaveerya was the emperor of Saptha Dweepa Mandala (seven islands). His wife was Sheeladhara Devi. They had 100 children but they died due to a curse of Sage Chyavan.
Deva Guru Brihaspati, advised the royal couple to propitiate Surya, the sun god, to get a heir.
Surya Bhagvan gave darshan to the couple and asked them to perform sapta saptami swapan vrat as it would wash off all the sins and bestow them progeny.
In sapta saptami swapan vrat, cow dung dumplings are placed in front of the houses amidst colorful rangolis. They are dried and are used for cooking. Cow milk is boiled in a vessel using the dried cow dung. Sweet kheer or payas is prepared using this milk under sunlight. This is then offered to Surya. This is performed continuously on seven saptami tithis.
Kritaveerya performed the vrat and got Kartavirya Arjuna as son, who according to Datta Purana, is an incarnation of Sri Sudarshana Bhagavan.