"I wish that all the women in the world were sexy and horny monster girls. There would be a sort of magic where once a "husband" and "wife" make commitments to each other, that's it. Neither of them can ever romantically or sexually love anyone else ever again. And love they do... Of course, those commitments can't be made until both the "husband" and "wife" were old enough, let's say around their twenty first birthday. There are some early and some late bloomers, but it's never more than a year's variance. Women in this society would grow up trying to find and seduce potential "husbands", but it's a very serious subject to them since it's a lifebond commitment. Men in this society are humans with greater strength (and libido) to handle a monster wife, and try to get girls attention because having more women interested in you means that you have more options for a potential "wife". Monster women have a hard time having children when you look at how much sex they have, but that allows the birth rate to be 1:1 when compared to the normal world. Monster women can have sex at the start of puberty, but can't have children until they've committed to a "husband". They use that time to get to know potential suitors. Any girl that's born will be the same kind of monster girl that her mother was, and boys will be born as humans. All monster girls have a vagina like normal women do and can only get pregnant through that, but only boys will be born through a normal human pregnancy while girls will be born through a pregnancy that's specific to whatever species of monster girl that the mother is. Finally, monster girls would be spread out appropriately depending on where the women in question lives now (i.e.: there won't be any mermaids in Arizona)."
And with that long winded wish out of the way, the stone glowed a bright light before magic erupted out of it, knocking Jon to the floor as the world changed around him...