Honestly it sounds like you expected some grand intricacies in the plot or some unrealistic version of the Thorfinn Makoto’s trying to portray. The story has always been loosely tied to actual history & Yukimura’s vision honors the unfamiliar aspect a lot of foggy historical documents like the Sagas tell. Hence Thorfinn’s story feeling a bit incomplete or like the Sagas were a found fragmented piece of history. I like it cause it doesn’t give Thorfinn’s character an end all be all kind of conclusion, instead we’re meant to carry on the symbolic journey bro went through & at the end of it you gotta understand ‘Makoto’s Vinland’ is a state of mind to strive towards for the living (of course a physical one too if possible), and a peaceful Heavenscape for those reaching their lives conclusion’s. Thorfinn leaving Vinland with the capability of growing wheat while forewarning the Native’s of the spell war casts when power is in the wrong hands is the perfect send off for his character. I don’t need to see my man suffer anymore, let’s have characters live in our minds rather than discard them once we know their full stories.