Eggers, mythological epic, stellar cast, expansive Northern European scenery — this all suggests it should be his strongest work, but I was left feeling a bit, well, cold. Northman is a feast for the senses — including a hypnotic, primeval score — and bears the visual hallmarks of an auteur, and yet it all adds up to a bit less than the sum of its parts. Nature, presented as a harsh and terrific force in The Witch and The Lighthouse, is present…