I wasn't aware of the fact that Damian tried to get into the Hall of Echoes far before you even turned into a Dragon Knight, but it seems pretty logical to say the least. (He wanted to get to his beloved after all)
But I'm not to sure if that's the reason he let you alive, after all - how could he possibly know you were going to get that far. He calls you a "whelpling" with other words a "minor problem" he put quite some Black Ring enemies against you, he certainly wasn't going soft on the Dragon Knight at all. (Except for himself doing the fighting, that is)
I have the idea a little more information regarding Ygerna will be revealed in the next Expansion, because if she is able to learn and get stronger in the Hall of Echoes, wouldn't any other decent necromancer/mage that ends up in the Halls be able to do the same thing? Which is quite unlogical. I mean I know she was forced to relive the same Memory over and over again, but she was dead right? just as dead as everyone else in the Halls of Echoes.
