Koakuma's recompense: That was... paragraph 898, B-12.... no, that wasn't it. C-12. .... Maybe C-13? No. No, it was 107 X-73, to be... sure? That isn't it either. Well... obviously Koakuma gets something out of the deal. She didn't just get talked around and droned at until she was fed up enough to forget to get some sort of reward for her effort. Right?
Family Tree, summarized: Koakuma sired Cosette upon the Nameless Female Thrall. Cosette thereafter seduced and ensnared a fairly wealthy gentleman by the name of Frederick Evans, and eventually had two children, Lily and Petunia by name. Whether they were his children is ambiguous, but in any case they found themselves in possession of his last name. On the other side of the family, Cepheus Potter finally 'settled down' and retired from the Auror Corps after his wife became involved in a rather traumatic incident which neither of them speak of after. A private healer is brought in, sworn to secrecy, and advises that it is unlikely that children will be conceived at this point. In spite of this appraisal, James is later born of their union, quite the surprise to many parties due to the couple's advanced age. Whether there was some measure of taint clinging to the wife, which incubated and hibernated through the conception of this child, is unknown. The family tree following this is fairly well known, however.
Kirisame: Will lie flippantly, blatantly, and almost pathologically, if it suits her purpose. Does not seem willing to break deals, however. Seems like it might be default behavior she can't escape, as the daughter of a shopkeeper.