Rashan is a Warder.
History
He and Bartol are bonded to Erian Boroleos.
He is possibly Domani, given that there is another character in the series named Rashan who appears in Graendal's palace in Arad Doman.
Activities
Erian reports to Galina Casban that Rashan and Bartol are suffering from her other Warders' deaths worse than she is. She comforts them in their grief.
Although Erian Travels to Far Madding with Cadsuane, she is forced to leave Rashan behind.
Erian feels Rashan and Bartol Travel suddenly from Cairhien in steps towards where she is staying in Tear. They are Travelling with Logain Ablar and Toveine Gazal, who are using the Warder bond to locate their Aes Sedai so that Logain may contact the Dragon Reborn.