How would you do Bra?

Easy! I will treated her as what she is: A dislikable character. Ashanark has describe it the best way: 

The main problem with Bra is not her character, it's how the story view her character.  That's the only change I will do; Stop the "character shilling" or blaming other characters for her flaws! And let other character call her out on her bullshit (Not like how U18 Bra did it! -_-). And maybe also make her afraid of death to make her character more unique (That will also explain why she always use senzu beans). And one last touch, Make her get killed in the majin arc by the "weaklings" to know that power is not everything. That way Bra will turn from the worst written character (in my opinion) to the best. 

The thing is that Salagir & Bra's fans don't understand is that most of people who dislike her are not "anti-Bra" or "haters". Being a "hater" means that you don't want a certain character to get a good development, you want them to disappear, die, or get even more bad so you can hate them. I don't hate Bra, I just dislike how she's written. If only Salagir will get this...      

You know mentioning people in Bra's life who deserve a bigger role yet no mention of Bulma, her own mother who isn't even a spectator in this series. Seems like an odd omission to me. 

I was talking the comic itself not you specifically, though the lack of care for any impact Bulma would have on Bra is a bit of a general issue.

The Majin Bra could have been played with her seemingly brutalizing her opponents at first, but either one of the Gohans or Piccolo notice it makes no sense for them to be alive since Bra could have killed them 10 times over. That would have let us know that some part of Bra is still fighting the control and her love for her family is still there. U16 Gohan could call out Bra on this fact, we see it shocks Bra, he challenges her to kill him. When Bra does kill Gohan she should be distressed and confused as to why she did it. Have her be conflicted the entire time. That way when U18 Bra confronts her U16 Bra's breakdown will feel more organic. The whole breaking out the Majin possession fully doesn't need to happen. The idea of U18 Bra getting through Bra did that job. The Majin possession did its job in showing Bra's existing character flaws and making her questioning herself. Lose the whole Vegetto will kill Bra angle altogether. It's not needed. Bra already showed she loves her family and doesn't want to hurt them. Bra being freed from possession and having to come to gripes that she killed Gohan while possessed. That would eat away at her more than anything Vegetto could do. It would be something Bra herself cannot pass blame to someone else. Since we already see past examples of Bra being a decent person, like her taking U19 promise seriously we the audience would know Bra's isn't pure evil. At the same time she isn't pure good either since Babidi could take possession of her. It showed us Bra is more complicated than we first thought and gives her I think a interesting journey in DBM. 

Honestly, I'd say that's the key problem with Bra. The story doesn't seem entirely clear on what her actual flaws and weaknesses are, and they seem to vary depending on where in the story she is. She can be an alarmingly skilled warrior with excellent technique who creates complex moves that other characters call out as unusual... or a berserker who can barely control her own strength, whose attacks cause massive collateral damage and whose Super Saiyan 2 is as wild as Gohan's once was. She can be a pampered princess, raised in the lap of luxury and sheltered from consequence, surrounded by admirers and doted on by her parents who often enable her worst habits... or an abuse survivor, who has had death threats hanging over her head practically since birth, who fears the other people in her life and desperately wants to be stronger mostly for the sake of survival, and whose only life seems to be endless combat training. She can be a fundamentally decent person, who is mostly crippled by personal doubts and a tendency to indulge in her worst habits and impulses but recognizes her faults and wants to change... or a complete psychopath who actively itches to murder decent people at the slightest provocation and who throws herself into the Majin transformation with complete gusto.

Now, these things don't necessarily contradict each other; one might say the definition of a complex character is one that can't be easily fit into your average two-dimensional archetype. (For instance, one can have great technique and a tendency to lose control.) And none of these things, by themselves, are bad. The trouble is that instead of complexities and greater depth, they often come across as the story picking whatever would make Bra look best in that moment. She's murderous and cruel when the story needs her to be a badass psycho, but a damaged victim when the time comes for consequences. She's the beloved wunderkind when it's time for fluff, and the one crushed by pressure when she needs tragic justification. She's wild, reckless, and out-of-control when she needs to be shown as dangerous, and a master of technique and pragmatism when fighting someone on her level.

What the story wants of Bra is for her to be a character capable of great good and great evil: a person who is well-meaning at her core, but waylaid by her neuroses into a darker path. The trouble is, we don't actually see many moments of Bra being an actual good person. Most of Bra's "good" actions feel more like things expected of her, and she often has to have her arm twisted into doing the right thing. Meanwhile, we have a lot more moments of Bra either being a huge jerk, or flat-out villainous. She does seem to have a sense of empathy, but anyone would feel sad and angry to see their beloved little quarter-niece be brutally killed, or accidentally harm her surrogate father figures. So the scales don't feel well-balanced.

I mean, hell, look at the whole Majin Bra thing. The whole idea of it is that Babidi is tapping into that bad side of her, the side that just wants to crush everyone who wronged her, in the same way he did with Vegeta. But the thing is, Vegeta still kept some level of control in the whole thing, because there were lines he would not cross; he didn't try to kill Trunks and fell short of killing Goku, and he even recognized when Goku pointed it out that the world was in danger. Vegeta, a guy who once slaughtered an entire village of Namekians basically for the hell of it, when having his absolute darkest impulses pushed to the forefront, still recognized that he had loved ones and the safety of them and the Earth was more important than his dick-measuring contest. It takes a bit of arguing, sure, but he still does it. Now, one can play this as a case of Vegeta having a stronger will and moral compass, but the fact is, Bra absolutely did not display any real doubt about her actions, and seemed to take active pleasure in butchering as many people as possible, including--hell, especially her loved ones. And the result is that while Vegeta displayed a clear arc of "starts bad, becomes less bad, goes back to good", Bra just kind of... stays bad, until she needs to be good, at which she becomes good.

Believe it or not, I'd actually keep her toxic personality. I might even emphasize more on her bragging and cheating. But there are definite changes I would make.

1. I would either give her consequences or not put her in situations where it's important that she has them. Bra's major problem is that she has circumvented every consequence that has come her way within the story by either off camera shenanigans, everyone blaming someone else (all of chapter 79 is utter garbage), or the plot changing its mind. That is how a Mary Sue is made, when the consequences of their actions, if any, become moot or someone else's fault.

2. More interactions with Goku and Vegeta. Bra is missing Goku's good hearted nature and Vegeta's pride. Having her interact with them more would help to bring this out considering they are both technically her father, and in their universe, they became the strongest. Imagine the character interaction if both Vegeta and Goku openly stated how disappointed they were when Bra teleported her opponent away, maybe with Vegeta even outwardly calling her a coward. Then Bra looks to Vegetto for support, but he doesn't give her any because he feels the same way they do. They can voice a lot of things in a lot of different ways that Vegetto can't.

3. More emphasis with Gohan. Her interactions with her big brother have been mostly satisfactory, however, I would've included a universe with a more serious Gohan, either one where he never stopped training after Cell or one where he managed to defeat the androids with Trunks. Personality-wise, Gohan has the perfect protagonist personality and has the power to keep up with the best of the best. More interaction with a more serious version of him would help demonstrate to Bra where she's gone wrong since the comic showed earlier that Gohan could get through to her even when she got angry.

4. More interaction with Pan. There has not been nearly enough interaction between her and Pan and it has hindered any positive qualities we could've seen from Bra. We know effectively Bra and Pan are best friends, but we're almost never shown this. If Pan, a good natured character, can care about Bra as much as she does, there must be good qualities to her. Let us see them. These two could foil each other greatly, working together as a team, while demonstrating the difference each child takes their lessons: Bra focuses on the power and training while Pan is focused on saving people. They're both trained by Gohan and Vegetto, yet despite that, Bra mentally went down a completely different path.

5. Use another word other than "passive." This was Bra's breaking moment, the thing that was supposed to make her realize the errors of her ways. It's an extremely important detail yet it massively hurts her character just because of which word was chosen. "Weak" the most cliche word you can think of, would've been a better option.

How would you do Bra?
But she's only 16!