While black and white can be done with beautiful villains and grotesque heroes, that does explain quite a bit.
Or the entire light bad expansion concept is thrown away when the Primus, Draka, Mograine and Vashj find a way into the living plane and wtf pwn the heathenous light users out of existence. One could hope.
Plus I personally like them because it’s interesting to see villains with an actual goal beyond “Kill everything now”.
The Scarlets show how otherwise decent people could get caught in their madness. You see this with Taelan;
“For so long, I have been a puppet of the Grand Crusader. What reason was there to fight against what the Scarlet Crusade had become? It has been decades yet the memories of my father; those precious memories, they are what have kept me alive”
Ya get the sense that like any cult they’re pretty good at boiling the frog. You don’t lead with the frothing evangelism. You start normal and gradually increase the crazy. Until even decent people who know this is really screwy have grown numb to the madness and figure they’re in too deep to do much about it now.
What would you suggest for the Scarlet Brotherhood then? The lid is well and truly off the crazy, there’s no more excuse of “Nathrezim behind the scenes” for them anymore and whatever good name the Scarlet Crusade used to have has been thoroughly stamped out by their actions for all to see - to the determent of these offshoots.
Well for starters;
Your average human might have heard some rumors about this or that bad thing the Scarlets did. But a lot of that’s according to the Argents, their direct competitor. Or worse yet second hand reports from the Forsaken of all people.
Yet you’ve seen them turn up and help people out’ve a problem the Crown either couldn’t or wouldn’t solve. Perhaps you’ve been misled about these Scarlets. Sure they’re a bit weird about non humans but they’ve lacked the cosmopolitan exposure you’ve had. I’m sure that’s just a byproduct of them living in the very homogenous New Heathglen. They’ll probably lose that once they get some fresh blood with fresh ideas.
Cut to the oft repeated famous last words;
“C’mon, how bad could they really be?”