Last night I was reading up on Norscan lore and became fascinated with the Skeggi folk stealing Cold One eggs and riding them into battle once they grow to adulthood. I think that's an awesome unit combo. I'm sure that there are more prominent Norscan characters to introduce, but Skeggi as a start position is very unique for the faction and allows for a unique mount and unit option that the other characters would not have. A Cold One mount for Norscan Lords exclusive to the Skeggi faction would be pretty cool. It'd also ironically perhaps be a way to make Cold One Riders be good! The Norscan ability to improve combat prowess with time in melee could really add a lot to shock cavalry.
Expanding into more controversial territory, I'm almost inclined to suggest Skeggi as more of an Untainted faction. Their lore entry on the wiki does mention that they worship the Chaos gods, but it is far less pronounced than with any of the other cultures that I read about. Also, there's an instance of them working alongside Tyrion when venturing into Lustria, so it could be viable.
Getting into an even whackier area, maybe the above Untainted could be optional. Perhaps certain buildings exclusive to Skeggi spread Untainted and reduce corruption, and these buildings grant access to the Cold Ones and maybe even some more (but limited) access to Lizardmen beasts. They could come with the tradeoff of losing access to units like Skin Wolves, Fimir, and Mammoths, as these are more Northern-based units that likely wouldn't be present in Lustria.
I'd imagine that the Lizardmen would be antagonistic towards Skeggi in either case - attacking them for being Chaos-worshippers or attacking them for stealing their beasts. But going the Untainted route could open up diplomatic relations with other Order factions to give a vastly different Norsca experience. We have a couple neutral factions that have decidedly evil subfactions, like Drycha and Arkhan, but we don't have the flip side yet of a relatively "good" traditionally evil faction.
I don't think that there's much lore for Losteriksson (ridiculous name), so I don't have a suggestion for what to replace the god dedication mechanic with. Obviously it would need some kind of Untainted counterpart to add depth to the campaign, but I haven't thought it through to that extent yet. It's still a hare-brained idea.