She used to break arms to enforce a gang's villainous will. This means she can never have a redemption arc. Is that what you're saying? Arm-breaking is irredeemable?
The reason Purity is so often chosen as a prime candidate for redemption is that she shows signs of wanting to pursue it. That's...really it. It doesn't take whitewashing to send her down a redemption arc. The fact that she shows she wants to be a better person means she's already seeking the path towards it.
No, I mean she breaks arms as a supposed hero!
"Breaking her usual patrol route, she headed straight to the northern part of the city and investigated the Docks. It was empty of ABB members, aside from two Korean girls were taking a break from turning tricks near the ferry, talking to their aged, fat, matronly pimp. Kayden resisted the urge to take action and run them off, resisted grilling them for information. She had done that last night with a group of dealers, and accomplished little to nothing.
The ABB was still active. Even with their boss gone, they were more organized than they had been under Lung's influence. But her interrogations had failed to get any details on why.
Even broken arms and legs hadn't hurt or scared the thugs enough to get them talking about what was going on."
Her first instinct when confronted with the problem of, "I don't know what's going on" is: "Better start breaking people's arms and legs."
******
Note, are there people who do that and then get better? Sure, maybe. But consider this: this is Purity when she's trying to be a hero, when she's turning over a new leaf. She doesn't even think twice about it. She just does this kind of shit.
What's fascinating about this is you think it indicates some kind of grand brutality or is particularly different from, say, Batman. Batman breaks a fuckload of arms. Here, she's just talking about chasing them a little bit, or maybe cornering one and talking tough, as far as we can tell.
And yet you pronounce this to be the most brutal, terrible thing, and it's not even clear she's thinking of actually hurting someone!
Real life Batman would be a fucking terrifying asshole.
Edit: Also, literally what? You're making up bullshit. The text plainly states that she wasn't THINKING of doing things, but reflecting on things she'd done.
"Breaking her usual patrol route, she headed straight to the northern part of the city and investigated the Docks. It was empty of ABB members, aside from two Korean girls were taking a break from turning tricks near the ferry, talking to their aged, fat, matronly pimp. Kayden resisted the urge to take action and run them off, resisted grilling them for information. She had done that last night with a group of dealers, and accomplished little to nothing.
The ABB was still active. Even with their boss gone, they were more organized than they had been under Lung's influence.
But her interrogations had failed to get any details on why.
Even broken arms and legs hadn't hurt or scared the thugs enough to get them talking about what was going on."
*****
Like, this was actually a debatable point until you started openly lying to support your conclusion.