The Kalevala is a strange beast. It was compiled by Elias Lonnrot in the 19th century out of an oral tradition. Lonnrot was deliberately trying to create a national epic, but he appears to have thought that he was rediscovering a lost epic. The result is a strange hybrid between genuine oral tradition and a composed national epic that fed on 19th century nationalism and 19th century ideas of epic poetry. The result is a product whose authorship is completely ambiguous and which is a weird amalgamam of 19th century values and ideas and ideas which are in many ways prehistorical.
The best way to approach it I found was to set aside the plot entirely and be swept away by the power of the language. The poem is immensely beautiful a feels like a magical incantation as much as anything. Much of it is explicitly a kind of folk mac, literally spells and formulas for rituals. The whole thing takes on that feel and is immensely beautiful. The stories themselves remind me more of folktales than proper epic poetry and Lonnrot has made an epic that I do not think was ever there. However, while Lonnrot has for the most part tried to scrub out Christianity, there is clearly material that is very old in the Kalevala and material that appears to be pre-Christian in origin.
The whole work is immensely beautiful. I don't think that it has a real unity the way the Iliad or Gilgamesh has, but it is very beautiful and feels like being trapped inside a folk magic ritual in a way that nothing else I know is like.
Well worth reading, but not quite what you might expect.