>>96418345
>>96418402
The truth is that Warhammer has never truly unequivocally formalised how souls work, even in the one book written as Manfred's own understanding of undeath.

As far as we know, souls leave the body on death unless proper funerary rites are done, and when the soul leaves the body it may remain stuck on the physical plane, make its way into an underworld, or be swept up by the currents of the realm of chaos and be consumed, either by gradually losing its identity until it dilutes back into the baseline nothingness of the realm of souls, or by getting preyed upon by a demonic entity, or by conjoining with other souls like it in a god; rarely, if ever, it may get a chance to reincarnate.
BUT all of this assumes that the soul is an indivisible unit, but we've seen souls split, or get split into its different constituents, which the nehekarans identified and manfred somewhat agreed with.
these components being:
the soul fire
the moral compass
the consciousness
the subconscious
the true name
the literal body
the literal shadow

with this in mind it is perfectly possible for a soul to be split in half by desecrating or traumatic magic and create a situation where someone's emotional "echo" might wander the world or an underworld or the realm of chaos as a ghost at the same time as that same being's conscious spirit half
and that is before we invoke the bullshit that is time flowing in absurd ways in the realms of the dead and the gods, which would even allow someone to commune with their own future dead self