In Oidheadh Chlainne Tuireann (The Tragedy of the Sons of Tuireann), the three set out to kill their father's enemy Cian. Cian is the father of Lugh, one of the greatest of the Tuatha Dé Danann. Cian shapeshifts into a pig to disguise himself, but the brothers shapeshift into dogs and hound him. They kill him, dismember his body and try to cover up their crime. In recompense, Lugh makes them quest all around the known world fetching magical weapons, which Lugh plans to use at the Second Battle of Magh Tuireadh. They succeed in obtaining all that Lugh demanded, but return to Ireland badly wounded, pleading for Lugh to heal them; but he refuses.
In at least one version of this tale, Brian is the clever and subtle one, while his brothers Iuchar and Iucharba are bumbling and easily overawed by Brian. This tale of the Sons of Tuireann has sometimes been likened to an Irish Argonautica.
Brian is one of the main characters in As Baile: A Story, a 2012 novel retelling the tale of the Sons of Tuireann.