I would suggest using either straight darkworld, or pure fabled. Either on there own can work amazingly well(Darkworlds usually with beatdown and swarm, and Fabled with spamming synchros).
Anways, without changing the focus, I would suggest replacing 2/3 gates with general discard cards since many of the fabled are beasts, and adding Kushano to work with gate and help discard the other fableds. Oh and maybe make space for Pot Of Avarice, very useful in fableds at least. Other than that can't think of anything.