I love Black Cat. I have her as an r4. However, I mainly use her against tricky opponents who have a lot of annoying abilities that trigger when you hit them since she's so good at shutting all of those interactions down. Whenever one of those abilities fails, she deals a lot of direct damage that quickly ramps up.
However, I've been curious to test her out against champions who don't have anything to shut down in order to see how much damage her bleeds can do when you focus on building up your cruelty and vicious passives instead. Her SP2 bleeds are critical bleeds, after all.
Turns out, they can do a ton of damage.
https://www.youtube.com/watch?v=ZT2p1wxiBaAYes, I know the boss has Bleed Vulnerability (that is, in part, why I chose Black Cat to begin with), but I still think it's a pretty impressive takedown if I dare say so myself. I figured I'd show it to you guys in case anyone else is as curious about her ability to deal damage when there isn't anything for her DAAR to exploit.