User blog comment:Hawkeye2701/Angelic Immortality?/@comment-1589281-20130626195058

Well one of the problem of "not telling you anithing" animes is that sometimes you can only speculate.

With no speculation I think that the answer is....what's a soul to begin with? Never explained.

To be fair the setting of eva it's a bit out of sense IMO.

"We built this giant city to protect a creature that can make human whole and thus perfect. However first we have to kill a number of giant immortal-over powered monsters who want to reach the creature we are defending because...we don't know. We also don't know when they're coming, but we got giant creatures that can defeat them...the thing is...they have to be piloted by children for unknow reason and we don't know if they work."

About decomposing, if I recall correctly, Shamshel body was decomposing at a very high speed. (I'm not trying to be aggressive in any way, it's just my opinion fare and square)