What was Cassian's experience with the Valkyries?

Cassian fought beside the Valkyries for five battles until they died at the Battle of Meinir Pass. The Valkyries fought when even the bravest males would not. Cassian fought against his superiors arguing for them to help the Valkyries. They beat him senseless, chained him to a supply wagon, and left him there. When he came to, the battle was over, and the Valkyries were slain. It took him a long time to get over that battle. His first lover beyond the Night Court's borders had been a bold-hearted Valkyrie named Tanwyn. She had ridden out for that battle and never returned.