You know... I've been pondering about a (kind of) similar idea as well, and I thought of a evolution (or stage) process to being corrupted.



"If a Faunus is hit during the 'rainy day', then the Faunus turns into a Grimm."



Then it dawned upon me: "If a human is hit during the 'rainy day', then the human becomes..." something along the line.



However, I've made a Grimm!Ruby so I am not/wasn't sure if I should follow with my fan-made/made up/AU theory(?).



The answer to your question/thought:



I don't think it's necessarily possible for Coco to be corrupted just by being near Grimm!Velvet (for like 24/7) because while Velvet was corrupted on that "rainy day", Grimm!Velvet was the outcome and other Grimm don't have the ability to corrupt therefore, I didn't apply it to Grimm!Velvet.



I apologize if my thoughts/explanation were/was confusing. (>A<)/