Plane of Exile
Vague distortions to the amorphous monochromatic backdrop prevent any sense of distance or scale, and there is only the choking haze filled with fathomless appetites.
Obvious exits: none.
In the total absence of the planar laws that defined your existence, your body and mind become fuzzy, stretched and indistinct. The degenerating atoms and thought patterns erupt into fecundity: billions upon billions of piths of nascent demonic life devour each other across timeless cycles. Your soul passes from demonling to feasting demonling before the torment ends, leaving not much of what used to be you.
Your remains slip away, recoiling to the Plane of Abiding...