Disclaimer: Even before Valheim I have always been fascinated with Norse myths. I'm no expert by any means but I like to think I know a thing or two. Point being that the old norse were superstitious people to say the least, and they sometimes practiced religious rituals meant to predict and influence future events. The practice was called Seiðr, or Seid, and was a cornerstone of Norse beliefs.
So like most of you, I have way too many bone fragments. I raid crypts for fun when I'm bored and they've piled up immensely. I've upgraded all my armors to max and have the bone shield, and stagbreaker, so for now they're mostly for occupying space. While not entirely analogous to the actual Seid rituals of yore, the buring of bones for the purpose of divination is a common enough idea, and one which (I think) would make a fun tie-in to real life viking culture, while also making bone fragments useful later into the game.
The way I figured this could work is as follows; You set up a hearth or bonfire, and while rested you can sacrifice a full stack of bones in the fire. In exchange, you will have the location of one point of interest chosen at random revealed and marked on the map. Most of the time(90%) this would be crypts/beehives/towers or other minor structures, but would still give you insight as to the locations of biomes and resources. On rare occasions(9%) the bones may reveal a more critical objective like a vegvisir or fuling camp. Least often(1%) they would reveal major locations like the Trader or boss altars themselves.
This gives bone fragments a purpose for the middle and late game, but still encourages exploration to find marked areas. You may know there's a boss stone some distance east of you that you need to find an altar, but the journey of getting there still lays ahead of you. And in a game filled with undead magic vikings and nordic monsters, it feels right at home with Valheims main themes.
So yeah, let me know what you guys think! I'm not a game developer so I could be pipe dreaming here but I'll appreciate the feedback regardless 🙂