Can a spirit become "completely disarranged without possibility of re -integration"?

[Minyatur]

But in the perspective that if a normal being dies, it will get re-born and if a ego dies, it will realize "Nirvana", what then will happen to a spirit that gets destroyed? And why is this undesireable?

You could see it as that nothing is sought to be overcome. Everything is rightful and "Nirvana" is both the initial and ending state from which all spring forth and all return.

I think we see a difference here because Ra resonates more with death at the level of where it stands than what it is at our own level down here. But it's really similar to the loss of the mind complex upon death except at the Octave level. In both cases it is an infinitely small portion of your infinite time/space space/time continuum of your greater wholeness and yet may always be seen as an infinitely huge portion of what you identify with.

Everything can be seen as infinitely small in contrast to Infinity, yet those with you where you stand will always be the truer other-selves in your eyes and for whom your emotions will most resonate with. These lost other-selves will be reborn among other other-selves and will walk the same stairways and most likely eventually rejoin with those they lost after having lived something unique of their own with other souls. Nothing is lost, something other and unique is born and all will rejoin.