You must fight your Uncle in a bare knuckle NHB match to the death obviously.
He has questioned your style has he not? And you his?
But watch out, once you kill your Uncle, yes you can force his now two bastard children into whatever style you feel is best for them.
But they will seek revenge after witnessing you karate chop their father to death in front of their tiny eyes.
Good luck, you have chosen a long road to walk.