>>212159413The protagonist could be BB, trained by her mom (only for self-defence, not to be an assassin). They could be even be sort of dual protagonists with no clear villain, Nikkia is on a path of righteous vengence just like Beatrix was, and BB is trying to protect her family from what she sees as an insane murderer.
>>212159733Maybe BB is a talented fighter but is overconfident; her mom wasn't nearly as hard on her as Pai Mei or her other masters were on her, so she's soft and inexperienced compared to actual assassins. Meanwhile Nikkia was trained by Elle in the harshest possible way and has become a ruthless killing machine.
Maybe neither of them know the true story of Kill Bill, Elle told Nikkia that Beatrix was an insane traitor and killed them for no reason, leaving out all the stuff about the wedding. And Beatrix just never told BB how many people she killed or why, or maybe even lied about killing Bill. She was just a kid when that all happened, and I doubt her mom would be open about it all.
You could centre the first movie around Nikkia tracking down Beatrix, who while still a killing machine is older and out of practice, and BB confidentally stepping in to save her mom only to get wrecked. She realizes her mom's been going easy on her, and she's woefully unprepared. First movie ends with Beatrix dying, and leaving a dying message for BB to forget about revenge, that she probably deserved to die anyway, and to live her life to the fullest.
Cue BB starting an intense training montage, setting up the next movie which is BB training and hunting down Nikkia.
Just spitballing but I'd watch it.