Okay wait, is Brothers in Blood actually.... good?
I mean, we all know how wacky that story is, but I've just been thinking about it a lot, and I'd like you to come on another journey with me while I over-analyze and give this arc way too much credit.
((Warning: we will be discussing Jason's canonical tentacles below the cut.))
Part One: Context. It's not just for the birds.
Brothers in Blood happens roughly a year and a half after Dick lets Tarantula kill Blockbuster. He's real fucked up about it, and feels responsible for that death, and sort of hates himself for allowing it to happen. The fucking BATMAN calls him out and tells him to get his shit together. That's how you know it's bad.
"You know the difference between shooting a bullet and failing to step in front of one."
Batman's being all angry and imposing, but he's really just telling Dick to forgive himself and admonishing his son for putting himself in danger because of a stupid mistake. Bruce knows all about letting grief ruin your life; he doesn't want Dick to go down the same path.
So Dick takes a year off. He puts away the suit and just tries to live a normal life. He leaves the ashes of Blüdhaven behind and moves back to New York. Things are going pretty good until they're not. Dick is in the process of finding a new place and reconnecting with old friends, when his sabbatical is suddenly (and murderously) cut short.
Part Two: Imitation is the severest form of flattery.
This is a Nightwing comic, so clearly Dick is our hero. Jason is celebrating the one year anniversary of stuffing a duffel bag full of human heads, so it's a pretty safe bet to say he'll be playing a villain. But it's a little more nuanced than that.
While Dick was away, Jason saw a bird-shaped void and opted to fill it the only way he knows how: by stealing Dick's costume and doing what Nightwing won't.
"Only one person whose attention I'm interested in..."
The true villains of this arc are the Pierce brothers. They own and operate multiple nightclubs, as well as a human trafficking ring, and plenty of other nefarious ventures. They also happen to employ all of the scumbags that Jason hunts down and kills. However, the Pierce brothers are notably two people, not one; ergo, it is not their attention Jason is interested in.
The person he's trying to get to is Dick, and boy, is he really getting to him. Dick is absolutely furious, but more on that later. Suffice it to say: Jason has his attention now.
Jason teases that they should share the mantle and keeps calling Dick "partner". He even taunts him about (big air quotes) "killing Blockbuster." By antagonizing him thusly, Jason is pulling Dick back into the life. He's forcing Dick to end his hiatus and be the hero he knows his brother to be.
Obviously, Jason's motives aren't entirely selfless. My guess is that he's only half-way joking about partnering up. The past year has been extremely lonely for him. He had his big show down with Bruce which quite literally blew up in his face, and we don't really know what he did after that. It was probably just a lot of bed rest and self loathing.
After Jason stops being useful as a plot device, Dick just leaves him behind to face the bad guy alone in an altered physical state (if you know what I mean). Dick tells his companion Cheyenne that the building is going to blow up, and she immediately says "What about Jason?", to which Dick responds "Jason'll have to take care of Jason this time." AND THEN HE JUST FUCKIN' DIPS.
That's literally the last time we see Jay in this story. For some reason they decide to tie that loose end up with a letter which reads:
"Dear Dick-bird. I survived and I'm all back to normal in case you're interested. Leaving town to find my own way. Thanks for coming for me, brother. I know we don't agree on much. I just wanted to believe we could be family again."
It's sort of difficult to read tone from a telegram, but if we assume that Jason is being genuine, this is just incredibly sad. The only reason why he was in New York was to try and rebuild his relationship with his brother, who just ended up abandoning him all over again.
Part Three: The best offense is a good defense mechanism.
It is a well-known fact that when it comes to killing, Batman is a sanctimonious asshole (Jason's words, not mine). While Dick tries his best not to murder people, he's not nearly as anal about it as his mentor. So I guess my question is: why is he being such a dick to Jason about it?
The answer is a little something psychologists like to call PROJECTION. Dick is gathering up all the things he doesn't like about himself and projecting those traits onto Jason. So much so that he literally sees him as a demon with horns and fangs.
Let it never be said that Brothers in Blood is subtle.
When Jason shows up wearing his colors and slaughtering people, Dick's secret shame is all the sudden front page news. Now all of New York City knows that Nightwing is a killer... but Dick's known that for a while-- and he still hates himself for it.
So all of this vitriol and hostility is only partly directed at Jason, but that doesn't make it hurt any less when he accuses his brother of being on drugs.
...way harsh. Like, I know it's 2006. It was still cool back then to joke about being on crack, but considering how Jason's mom died, this feels like Dick is just poking the homicidal bear.
I already mentioned in Part Two how he leaves Jason to fight the bad guy alone in a building that's about to blow up, but really I think the shittiest thing Dick does here is when he says this:
My jaw dropped when I read that. On the next page, he says he'll put Jason at the bottom of the East River. I was so tempted to just write this off as an OOC piece of shit story, but if we're jumping through all these hoops to redeem it anyway, I'll just say this:
Dick is experiencing a lot of anger (something that's actually very much in character for him) and in his anger, he says and thinks some things that he doesn't actually mean.
We could also chalk this up to projection again, and say that Dick is really wishing he himself had died. It's still not great, but it's a little more palatable to me if you want to think about it that way.