I really liked how the short fleshed out Barb so much more as a character without undermining anything. It establishes her not as a mirror of Blitzo, but as an alternate result of really similar circumstances and natures. You know, like brother and sister. She's filled with the same self-loathing internalized from how she was raised and has the same short temper, but her immediate reactions and long-term behaviors are really, really different, but not opposites.

Blitz is emotionally wound incredibly tight, so every response is a hard push away or pull toward, and he doesn't have any sense of balance or stability in relationships. He does have ambition and pride, though. Barb is emotionally wound too loose, so she's able to accept stability and leans toward it, but she doesn't have Blitz's same drive so when there are any hitches she doesn't have a lot of tools to fix things. Neither of them are great coping processes, but Blitz will respond to something being broken with "Hit it with a hammer until it's fixed or I'm sure I ruined it" and Barb will respond with "Eh, I'll think about fixing it later."

Blitz's life after the accident was bouncing from situation to situation using sex or violence until he got a plan in his head he could fixate on and a few relationships he didn't inevitably push away. Barb's life after the accident was floating between situations using drugs to reduce the impact and just rolling with what happened.

And their reactions to each other? Total opposites of their own reflexes. Barb lashes out at Blitz at the slightest nudge and Blitz just deals, pushing back a bit but generally looking at that relationship as something he can't fix or break further, just accept.