User blog comment:Xilinoc/Ch. 630 - The Twinned Twilight/@comment-24726378-20150611162918/@comment-5693502-20150611180942

Well, if Yhwach's Soul Distribution power is anything to go by, it would make sense. The tragedies caused the Quincy's soul to be damaged in a way it couldn't heal itself; then in steps Yhwach...