How keep keep stray cats away?

So people two houses down has a male cat that keeps coming up and fighting ours!!! Ours is fixed and theirs is not!!! They r very hateful about the whole thing!!!(also has shot multi dogs and chickens for no reason)

I would like to keep from getting so bad that it leaves no chocie but to kill the cat (like putting them down due to wounds and such)!

Plz if any advice and anyway to keep him away let me know!!!

I would also like to ad that im sorry its not prego related and that our animals are in a fenced in area and the cat still gets in and fights!!