He's probably realized that having a married Julius to a wife Ourtzen can "influence" (cough) control (cough) is advantageous, particularly if the wife is capable of defending herself, doesn't detract from the mission, is someone Julius actually shows strong, positive feelings for, etc.---basically, someone Ourtzen finds "tolerable" as compared with someone the King might pick---since it's pretty clear that the King will pick someone if Julius doesn't get married soon. LOL. I wonder if the king threatened Ourtzen? >_<
Hmm... Though, it is definitely suspicious! >_<
I'm also thinking that since they prematurely whacked the step-mom, there must be something worth keeping secret, and thus, they are willing to do almost anything to keep hidden. Likewise, despite the fact she's back from limbo as a sacrifice to the Demon King, can they even kill her? I ask because wouldn't those assassins have tried to do that to the MC if they could? I feel like they have to keep her alive since she's a sacrifice and all. =P