Dev already stated multiple times that he has no wishes on adding Futa.
but Yandere? we got BloodLust traits which makes Lona Happy after any kill count(i think except for parasites).
The island of noer lacks the desirable men, or they all died, its just a land full of sorrow and despair, love is merely a tool for exploitation in it.
If I remember correctly it was Lona being a futa since it would be too much work I don't see why a NPC can't be one
Also never said that a yandere characters would have to be attractive it would also be fair to assume peoples idea of love would be warped similar to what we already see with that pighead fertility cult or the woodson family