The PCs decided to approach Armin Pot-Thrower of the Arnorings to find ways to end the feud between the two clans. After considerable back and forth, he eventually agreed to a deal by which the Arnorings and the Orlmarthings would hold a joint market day each season at which pots, wool, and iron would be sold. The Arnorings were also granted the right to cross the Orlmarthing tula by its paths. If any violence broke out, it would be adjudicated by Yanioth Brandigorsdottir. He also warned the PCs that Erianda the Red was planning on stealing an Orlmarthing clan treasure from them.
This deal does not, in itself, terminate the feud. But it does lay the groundwork for it, making a permanent resolution much easier. If the markets and safe passage go well, it will gradually reduce the difficulty to negotiate a permanent end to the feud. Ending the feud is not the same thing as making an alliance, but doing that will also slowly get easier, assuming that violence does not break out between the clans.
Armed with that knowledge, Sindri and Yaneg plotted a trap for Erianda. They concluded that she was planning on stealing the Eye of the Half-bird, so Sindri decided to put it into his head, cutting out his own eye to do so. When the attack came, the PCs ambushed her, defeated her and her darkness demons, and forced her to swear that she would not attempt to steal the Eye again and that she would owe Sindri a favor.