General Winter I do not know - he comes when Muscovy calls him and... I think he is not dissimilar a being to our young Jack Frost - a bringer of winter. Muscovy says he has a pact with him - protection for the permission of winter to rule his lands.

As for the Frost Wyrms... I do not know. They are whispers and rumors only. But in my world not all dragons breathe fire. The cold-drakes did not have flame at all, and rumor whispers that to some of them the Enemy gave breaths of frost and cold, instead.