I agree - trying to write respawning into lore raises more questions than it answers. Particularly why significant NPCs never manage to hit the window between zero HP and death that allows them to aetherially drift off to their home point.

The "aetherial respawn" would make more sense (but worse story) if characters dissolved into aether, FFX-style, upon death. The lore suggests that it should work that way - in which case there would be logical layers of near-death experiences:
1. Zero HP/unconscious but able to hold form; able to be revived
2. Critical negative HP that triggers physical dissolution of the body; soul has enough energy to "hold onto" its aether and find its way to an aetheryte beacon
3. Second critical point, soul can no longer hold physical aether and death is permanent.

From a story (and in-world!) perspective this would be pretty awful though, as you'd have no certainty that a person was really dying or was going to be perfectly fine.

(...oh, wait! Maybe that's how Gaius survived in the end!)


I guess perhaps a variation could be seen in-game that the first two levels work the same, but at the third stage the body doesn't have enough energy left to instinctively dissipate and instead remains in physical form.

I still think it would be easier to not try to have a lore explanation for respawning, unless it's really well-integrated and used as a plot point elsewhere. When aether, life and death are so central to the story, it's awkward having this "get out of death free" card that's apparently available even to non-Echo-blessed people.