This Awful Fragrance (BG, ABO world)

Remona was supposed to be a winner in life.
A rare omega, member of the Duke's family, whose appearance Helen of Troy woud envies.
But unfortunately, she never got to see her own beauty.
Unfortunately, her family was heavily in debt.
Unfortunately, she was the only Omega in all of recorded history who smelled like rotten eggs, which even the Alphas would run away from.
Unfavored and lonely, Remona was sold For marriage, to an ugly and sadistic count.
But why the horrible person in the rumors would releases such lovely pheromones?