!SPOILER!
We know that Rugga lived, or simply stayed, in Arberrang before Boersgard. We also know he tried to depose king Meinolf, failing. Dagr is a deadly warrior, not only for his blade, but because of his steady nerves and the good capacity to reject pain that sports when we execute him after Rugga's betrayal (Chapter 10).So there's my first possible story. This facts lead me to think he was trained by good masters, almost certainly in Arberrang, where we suppose he met Rugga, and which better training than the king's guards training? Rugga's speech potential is so high, maybe he convinced our Dagr to substain him during the coup, pheraps as a spy/informator. But their bond isn't a common bond. I'm sure Rugga's wit permitted him to strike in a psichologycal weakness of Dagr, possibly about his past; Dagr begun to trust completely Rugga. The coup begins, Rugga's forces against king Meinolf, but soon the plan fail, leaving him trapped in the city with Meinolf ready to counter-attack. Dagr is scared for Rugga's fate and he try to advert his new leader, too late. He has a few moments to explain the situation, allowing Rugga's remaining forces to stand in a weak resistence, in fact, Arberrang's guards push them despite the failed ambush. In the fight, the future Boersgard governor lose his right hand and a guard rip his throath trying to slaying him. Dagr defends him till the escape; the traitor is captured with a few others. Meinolf immediatly order to cut Dagr's tongue and he's locked up in the prison but, with a dexterty action, he escape after a few days, reunioning with Rugga in a near village (Tolir?). The journey to Boersgard begins.
That's my immaginative chronicle, I had a lot of fun composing him and I would be glad to see your own story of this mysterious character. Skall. ---davr 20:46, 28 July 2019 (UTC)