They did foreshadow it though. In the wedding phase of the story, and before that with how the only persons she seems to allow to touch her are Tia and Zeno.
I was angry that they took her a first, then I remembered 2 things:
1: She probably can, and will, kill them all if she wants.
2: The MC freaking lobotomized her the 1st time we saw her.
It's kind of trash (not the translation and stuff, I know it's hard), but it's still interesting to see a protaganist that isn't from a world void of magic.
Christina would be a good match for cid, they are both sadists (depends on the type of person suffering though) and she's already close to figuring him out as shadow, while his sister and fake ex-girlfriend are clueless.