But to be the devil's advocate, can we turn a bad man into a hero...
I say we can. That is where we can get some delicious conflict into our stories. For instance, how can we take Heidi's look here Sir Guy, he, the one Maid Marion has forsaken for want of the rather wimpish Robin Hood.
The Fair(ly dark haired) Maiden might forsake Sir Guy and everything she knows and understands, to go live in the forest with a load of well meaning hairy blokes. But all they know and understand is bad jokes. If they had television, it'd be stuck on the sports channel. Their favorite past-time is shooting arrows at trees. Like dah! There are mosquitoes in the mossy glen. In winter it snows. And she's still eating Sir Guy's deer, but charcoaled instead of gently prepared in great kitchens in the bowels of his castle... And Robin, he who she has held so close to her heart hardly ever looks at her.
THIS IS NOT the same Robin she has hitherto loved. He's a sodding selfish little wimp who complains all the time. He's not doing the rob the rich to give to the poor thing for altruism. He's a wimp and needs a crutch to show off with. And it all gets put into perspective as:
In the dark of night she remembers the flashing eyes of Sir Guy. The lust and the sheer force of his personality. And the strength of his convictions. And what she had misinterpreted as acts of brutality were, indeed, for the good of all, not just a chosen few. And...
Examine the bad guy Rhett Butler. Now we got Rhett the flashing dark eyes and the lust and the romance. We got the pheremones in soup ladels, all of which we (Scarlett) spurned for ... yes Ashley (Robin Hood). And there was Rhett all along, the ultimate bad guy.
Didn't sign up to fight 'the cause'. Gun Runner, ammunitions - made heaps of money doing it. Whoring around the place with Belle Watlins. Bribing his way out of jail by cheating at cards. Why that man didn't even come home with Scarlett and Melanie and her snottie nosed little toad. Instead the man had the hide to steal a kiss from her then dash back into the flames of Atlanta! So how do you turn around a bad guy like that?
So you see? You can make a bad hero good.