It's a plot point later in that Kyrian abomination quest that unlike Maldraxxi the Kyrian maintain themselves and the soul stays in the body, which is why the abomination is happy to cooperate with you. The two goons in front of it argue about how they need to evict the Kyrian souls and put a Maldraxxi one and how the Kyrian use brainwashing, unlike upstanding necromancers like themselves.