MAybe we are overthinking and it is just that we haven't done all 3 at the same time. Or 2 until we meet the door and then the third.The issue is that our Soul is apparently Empty, outside of whatever the fuck is behind the Gate.
Unless...
Unless the issue is that we need to fill that space first...
Shit, that might be it too. The Gate will open on it's own once we've filled the empty space that is Halla's apparent Soul with a Story, or something.
We could try imagining a recreation of the grove of sacred treesfrom the marriage post.
Or a cultural practice that could have to do is raising runestones? Could relate to filling that place based on stories about us. (Following the themes of stories/reputation in norse cultivation observed so far)