Board Thread:General Discussion/@comment-25093611-20160418185713/@comment-27565137-20160508174903

To be totally honest something weird has always been going on there. So hollow reiatsu can be lethal to quincies but before invading Soul Society they go to Hueco Mundo to find the strongest hollows and recruit them into the Quincy army.

Maybe. Yhwach was the one that introduced that flaw into the quincies. Just think about it. Yhwach needs the fragments from his soul to return to him periodically, or else he would start to regress back into the state he was born. Incapable of using his own body. So he introduces that flaw into the quincies so to in a way, give them a reason to fight the hollows. If a quincy died Yhwach soul fragment would return to him, but even if the quincy didn't died immediately, then the hollow reiatsu would act as a poison that would debilitate or kill the quincy over time. In each case Yhwach would gain another one of his soul fragments.

Also the soul destruction thing. Seems more like an excuse the shinigamis made up, to have a reason to hate and fight the quincies. Maybe once Ichibei or the Soul King realized who Yhwach was gonna become, what he was... They decided to come up with that false information that quincy powers destroyed hollow souls, therefore creating an imbalance in the flow of souls between the physical world and the spiritual world.

Most likely when a hollow is destroyed by a Quincy. The soul instead of going to soul society, it went to the Dangai dimension, where the souls travel to be reborn into human beings. Yhwach was always going on about the Soul King betrayal. Maybe that betrayal was just that. The lie that was created to justify why shinigamis had to destroy the quincies.