Well anything the devil does, God can do better because He can do it with pure righteousness.
I’d say why not costumes of things that represent good things that Christians can do. Not axe murderers, say, but doctors and nurses. Or construction men or plumbers. Even hunters.
And instead of trick-or-treat, go out with a God Bless You and, while accepting the treats if offered, pass out gospel tracts to the homes. (Yeah I’m a Crazy Evangelical.)
Not bad ideas, but I would pass out Catholic literature.
Our kids at the Mass tonight dressed up like a saint.