Ahh gotcha, glad you got the next part of the village but sad that Gunnar heart hasn't appeared. I would have to try for myself to see if I could find it so I can give you an absolute answer. The only thing left that I can think of is the battle you have with him and how it ends, you can also repeat the battle later on if you meet him at the river bank. Maybe repeating the best action in the fight may increase his like just like how doing the bad one will decrease his like. It's the best I can think of at the moment and I'm not sure if I can change my liking with him to check this theory out.