it would be a real shame that after reforming his character and bringing joy to the world, his name would survive as a byword for being a proper nasty. I guess once you make a name for yourself that's it. He's fictional though so it doesn't matter.
"That guy's a real scrooge."
What, he's a miserly so-and-so?
"No, he was, but he completely reformed and is a lovely generous chap. You know, a 'scrooge'."