Cassandra's behavior in Batgirl 2024
I think that we all have been misinterpreting what Tate Brombal is doing in the current series. We're forgetting to take Jayesh and his death at the hands of the Unburied into account. I suspect that Jayesh and his daughter are more important than Lady Shiva when it comes to why Cass is being so vicious, especially at the end of issue 12.
An interesting and important aspect of Cass is who she feels loyal to. In the 2000 Batgirl series, Barbara and Stephanie are important to her emotionally and she respects their advice, but her guilt and need to make up for her crime causes her to ignore their attempts to get her to have fun and find a role in society.
We all know that Cass will obey Batman's orders even if it means ignoring Barbara and Steph. The Gotham War and Chip Zdarsky stories in the Batman comics show her siding with Barbara and Dick against Bruce, so she may now have reduced her loyalty to Bruce and be favoring Barbara and Stephanie over him.
It's important to remember, though, that the civilians in Gotham have been shown many times to be her top priority. She'll obey them even when it means disobeying Batman and ignoring her internal moral code. I think it's because she has a nasty inferiority complex connected to her guilt and feels that civilians are more moral than she is.
In Batgirl (2000) #2, she's focused on rescuing the man and has no interest in shutting down the mob group who kidnapped him. Her anger and guilt over his death lead her to do an all out attack on the mob in the ex-prison. I find it funny that, if they hadn't been so cruel, they wouldn't have been arrested. She also obeys the man's request to deliver a letter to his wife.
In Batgirl (2000) #16, Cass is willing to let the first criminal she finds go, as she's obeying Tim's request to stop his father and not arrest him. She only arrests the father because he's a remorseless killer. She's upset at not fulfilling Tim's request and tries to make up for it by returning to him and escorting him home. I consider the fact that we never see Cass checking up on Tim after that issue to make sure he's safe when it's likely that she removed his only parent to be a weakness in Kelly Puckett's run.
In Batgirl (2000) #19, she lets a criminal get executed only because a civilian requested it. She ignored the police's demands and the fact that it's the day she committed murder and her internal pain in favor of the request of the mother of the person killed by the criminal.
In Batgirl (2000) #48, she's trying to rescue a baby and bring them back to their mother. She ignores Batman's orders in favor of focusing on the baby and mother's needs. She even is willing to yell at Batman and disagree with him because she's more worried about the people on the boat.
In Detective Comics #986, she's unwilling to abandon the scared children near the bomb even though she has no idea how to defuse it. She's unwilling to leave them to be afraid and die on their own. They have to have company even if she can't save them.
In Birds of Prey (2023) #25, she blows up a rock and agrees to have a picture taken purely because the workers at the quarry want it. Her posture shows that she's not interested in the activities, but if it makes civilians happy, she'll obey their requests.
As a result, I suspect that it's not her mother whose requests are influencing Cass in the current series, but Jayesh's requests. When she begins chatting with him in issue 3, she learns about his daughter and that's when she takes the Order of Shiva seriously. When Shiva requests that Cass work with the League of Shadows and Blood in issue 3, Cass disagrees. She only takes the idea seriously when Jayesh makes the request in issue 4. When he says he's the least important person in the room, he doesn't realize that Cass considers him to be more important than her. Cass' move from asking what Batman would do to asking what her mother would do at the end of that issue is likely because Jayesh is asking her to work with her mother and she's doing the same willingness to ignore her moral code at the request of a civilian that she showed in Batgirl (2000) #19. Cass is certainly feeling guilty over her mother's death, but Jayesh's death is certainly impacting her, just like the civilian death in issue 2 caused her to violently take down the entire mob group. It's probably not a coincidence that Jayesh's daughter, now working with the League of Shadows, is who arrived in issue 11 to request that Cass attack the Unburied. In issue 12, Cass mentions in her report that she doesn't trust Nyssa but she does trust Jayesh's daughter.
We have all been focusing on the interactions between Cass and Shiva and they're definitely important, but I think that her true motivation and reason for being so vicious may be her attempting to follow Jayesh's wishes, not her mother's.
[EDIT] Of course, the death of the people at the restaurant she regularly visited are also a large part of why she's losing control. They were brought up in issue 6, saying how upset she is at their death.