I think you might be jumping the gun a bit, and misinterpreting that scene based on awkward machine tl. Checking it and the rest of the dialogue with other translation sites, it reads more like the normal lewd magic stuff that all the girls are going through.
The dialogue is actually something like:
Lord: “Don't worry. With my magic and the penis ceremony, you'll be just like us.
You'll be able to enjoy being lewd and dirty all the time.”
Lord: “All you have to do is think about nothing else and keep your head full of cock.”
Arika: (I understand, if that's what my beloved husband says... then a bitch like me should not think about anything else)
Maybe we will get full on demon corruption stuff, it’s not impossible, but this dialogue is not really hinting at that, no more than anything else in the game events have. Don’t go jumping to conclusions too early lol. I also don’t think there’s anything about her Soul in there, he just gets her pregnant and now she belongs to him.