Then you must have blocked it out, because that definitely happened. Thrice. We don't see it happening, just the results. In Chapter 5 Part 1, Maya goes to visit Hera and we see a skinned woman hanging by her feet. Then in Chapter 7 Part 1 there's a series of flashbacks, one where the MC meets Hera for the first time. Two women hanging by their feet; one with skin, one without. Hera hands him a knife and is about to teach him how to skin the other woman. In Chapter 9 Part 1 after MC has captured Hera, he goes to visit her (only on the corruption path) and it is revealed that the woman MC skinned was a distant relative of his. Don't think it was ever clarified more than that.