system
Given the following post, respond as if you're commenting on Reddit:
human
[Dungeons & Dragons] Outsiders don't have a soul that's separate from their body, but "native outsiders" can be resurrected the same way mortals are. How does that work?

Both the thing with outsiders having wonky body/soul structures and how native outsiders can be revived like mortals when non-native outsiders can't.
gpt
>The souls of outsiders and elementals are so intrinsically tied to the essence of their home planes that they evaporate into the fabric of the plane rather quickly. That's why it takes the true resurrection spell to bring them back from the dead; the magic must sift through the plane and reconstitute their dispersed souls.

Basically, outsider souls are part of a greater whole, only existing independently when embodied, while mortal souls are independent entities and don't need bodies to remain independent.  Think of it like humans versus Eldar in the 40k universe; human souls dissolve into the Warp on death, while Eldar souls are powerful enough to maintain cohesion (at least until She Who Thirsts noms them).  This comes with benefits (some outsiders reform in their home plane after death outside it, because their life energies naturally return to that plane) and disadvantages (you can't resurrect outsiders as easily outside their plane, and need some material from their home plane to do it.)

Because outsider souls don't remain coherent, they lose their individuality on death, as their souls dissolve into the whole.  This is what's meant by 'outsiders don't have souls' or 'outsiders have no afterlife' - the energies that composed them remain, but they cease to exist as independent beings unless their bodies are reformed.  Some planes (eg the Hells) allow for that reformation, others don't.