Huna isn’t recorded until the Liber Eliensis (LE, Book of Ely, 12th century) and by Marie de France in her Vie Seinte Audree (late 12th century).
Huna was a priest at Ely and Æthelthryth’s personal chaplain, whose advice on her salvation she valued and who taught her the teachings and deeds of the saints (LE i.15, 18). According to the Liber Eliensis (i.22), he was the priest who presided at her funeral. It claims that he joined her at Ely where he took his vows. After her death, he left Ely to become a hermit on an island in the fens called Huneia. He was considered a holy man and his grave on the small island was known for producing healing miracles. Both the LE and Marie refer to him as a saint. His grave was opened before the 12th century and his coffin was moved to Thorney by people wanting easier access to his healing miracles. St Botulph‘s relics were also relocated to Thorney under the orders of Cnut, so that St Huna was in the company of one of the major East Anglian saints. His feast day is celebrated today on February 13th.
The LE and Marie de France both link Huna with Ymma, Owine, and others who served Queen Æthelthryth. Although they say that Huna joined her at Ely, it is possible that Huna had also been with her in Northumbria. If he only entered the church when she came to Ely he progressed very fast for him to be the lead priest at her funeral only seven years after her arrival. Note the similarity between the names Huna, Ymma, and his brother Abbot Tunna. No source claims that Huna was related to Ymma and Tunna, so it may reflect a naming style common in East Anglia (not unlike her father King Anna son of Enni).
Janet Fairweather, trans. Liber Eliensis: A History of the Isle of Ely from the Seventh Century to the Twelfth. Boydell, 2005.
June Hall McCash and Judith Clark Barban, trans and ed. The Life of Saint Audrey: A Text by Marie de France. McFarland, 2006.