Emma was never afraid of Killian's dark past. Bc she knows he truly changed. That he's a genuine hero.
Her trust on him was honest too.
When she wanted to save K by turning him into a DO too. And at the end she was right . He was the hero
I'm a fan of true love

She's so confident about his redemption. More than himself

"That's quite a lot of faith you're putting on me Swan"
"I know"

Her constant trust on his goodness. She didn't even think that his happy ending was a problem with the "villains don't get happy endings" rule like with regina, bc she knows he truly became a better person