What if "Not Vriska" is Mindfang and Summoner's non-ecto descendant? (Well, at least the one who got most of her DNA from them.) After all, the Alternia timeline in game is "some time passed after the Summoner rebelion".

… You know, for some reason I had not even considered the fact that it’s actually not hard to imagine that some of the Ancestors, specially the Higher Bloods, did do the do at some/various points in their lives. That’d be an interesting thing to see if it’s brought up in Hiveswap.