One of the things that I love about this game is the first two fights. They're extremely iconic, visually and mechanically interesting. Classic RPG. And it got me thinking about WHY they're good and why some of the other fights aren't as fun.
I think one of the things that really makes those two stand out is they're emblematic of the challenges in their respective biomes.
For Eikthyr I think it would be good to add rain to the weather effects during the fight to really make it about that first struggle for survival against the elements. Adding the wet effect would make the fight a touch more challenging but not horrible.
Elder is perfect IMO, I love that boss.
Bonemass, while I dislike the fight it is does represent the swamp and I think having one boss that's just an HP slog is ok.
Moder is where I think we start getting in to room for improvement. The mountains are all about battling the cold, I think adding maybe being able to bait her down with bonfires and have her be weaker to physical damage when in the effect range of the fires would make the fight more about strategy and preparation, and more about what that Biome really is.
Source: https://www.reddit.com/r/valheim/comments/vid5by/boss_fight_ideas_spoilers_if_you_havent_done_any/
