He beats himself up both emotionally and physically. It's a hauntingly realistic look at someone with such self-loathing they are completely broken and don't know any other recourse than to hit themself.
Episode 3 - Better Goff Dead
No one on the team, besides Vigilante, sits well with the idea of killing the Goff children. Murn initially tells Peacemaker he won’t kill them, per his request, but that immediately changes when Murn realizes they're all butterflies. Harcourt and Smith are visibly shaken after Vigilante slaughters them with brutal efficiency.
Episode 4 - The Choad Less Traveled
Towards the end of the episode, Peacemaker has a flashback to his childhood, when his father forced him to kill a tied up man with a sick look of satisfaction on his face as his son went through with it while crying his eyes out, which then transitions to a flashback of him killing Rick Flag and Flag's last words to him, which then transitions to his happy memories with his brother up until his brother died. It just goes to show how much of a damaged person Peacemaker is.
You wouldn't think someone being broken up over failing to kill their friend's father would be heart wrenching, but Vigilante telling Harcourt after being bailed out of prison that he might've made things worse by failing to kill Auggie and trying his hardest not to cry manages to be genuinely sad thanks to both the music playing and the fact that Vigilante can barely get any words out, which is in stark contrast to how much of a Motor Mouth he usually is.
You can tell from Peacemaker's tone as he describes Batman's modusoperandi that he is deeply upset and frustrated by what he sees as a farcical and disgusting eternal engine of human suffering being glorified as heroism by idiots.
Episode 5 - Monkey Dory
When Chris is talking to Leota, she tells Smith that he isn’t an inherently bad person and gives him advice. He gets choked up at how he had never had a deep, meaningful conversation with anyone up until that point. This is made worse when Leota plants the fake diary from Waller at his place. She clearly doesn’t like what this job’s making her do, but she feels like she has no choice but to betray his trust.
Episode 6 - Murn After Reading
In the beginning of the episode, the Butterfly in Murn reveals how every morning, it has to experience every single memory of its host, mainly the bad ones. It's clear that despite knowing it was possible Murn could change, whatever he's done in the past disturbs the intergalactic bug in control of his brain and body. Alternatively, what bothers the Butterfly are the vestiges of Murn's better nature which were condemned into oblivion with all the nasty parts. Still, you somehow end up feeling sorry for an extraterrestrial parasite.
When Chris is doing a show-and-tell for a class of grade school kids, one child asks if he has an origin story. The otherwise funny scene suddenly turns much more subdued, as Chris can only think back to his traumatic childhood and mutter a sad "not in the traditional sense."
Vigilante, despite being a lunatic with self-admitted difficulties actually feeling normal human emotions, makes it clear he's worried because his best friend is gone.
Peacemaker finally admits that he doesn't want to kill any more. It spills out of him in a rush, it's something he's ashamed of. He's scared to admit it.
Episode 7 - Stop Dragon My Heart Around
In a flashback, we see how Keith Smith died - Auggie forced Keith and Chris to fight each other for his bigot friends' amusement, Chris got in one lucky punch, and Keith fell backwards and smashed his head on something. If it wasn't for that one punch, the entire course of Chris' life might have proceeded very differently. It goes a long way towards explaining why Chris hates himself so badly.
Earlier in the season, Waller told Leota that she had "god-given talents" that she was wasting at her old job, creating the impression that she had some sort of background in intelligence. Here, interrogated by a furious Harcourt about her framing Peacemaker, Leota finally comes clean about how she ended up on the task force - she lost her old job, and desperate for money, she turned to her mom for help and was goaded into joining Project Butterfly. What was her previous job? She ran a pet-care center. Even Harcourt has trouble staying mad at her after realizing just how far out of her depth Leota is.
The death of Murn. His last moments are spent with Harcourt tenderly holding him in his true form.
Harcourt's reaction shows her regret that one of the last things she said to him was clearly offensive and hurtful towards him, the essentially racist comment that she didn't know "how his weird butterfly brain works."
Chris's reaction to killing his father. Auggie absolutely deserved it, but that unfortunately doesn't change the fact that Chris still loved him, and he just falls apart completely after the deed is done.
Before he kills him, Chris beats him up and says he was responsible for Keith’s death, and admits to being an awful person for letting his father corrupt him for so long and for not killing Auggie sooner. He sounds both absolutely furious and guilt-ridden when he says this.
Auggie's verbal beatdown of Chris is really hard to listen to, especially hitting home for people whose parents have rejected them due to their sexuality.
Chris clearly takes Adebayo's betrayal very personally, and now wants nothing more to do with her after this mission. Whatever bridges had been steadily built between them over the last seven episodes are naught but ash. Leota's look of hurt says it all after that.
Adebayo: Chris... I just wanted to say... I know what I did. And I'm sorry. I shouldn't have- Peacemaker: Forget it. I don't give a fuck. You said we were a team, that's obviously not the case. I just can't wait 'till this is all over, so I never have to see your stupid, dumb face ever again.
Episode 8 - It's Cow or Never
Economos admits he dyes his beard, but it’s given a bit of a dramatic twist. John does it because it makes him feel attractive and because he doesn’t have any friends or relationships due to being lazy and overworked. He then goes on to say that he thought nobody even cared enough to notice, until recently when someone has been making fun of him for it. Meanwhile Peacemaker and his teammates are listening in on this whole speech with Peacemaker's face being absolute stone, clearly realizing that all his careless jabs actually had an effect on this lonely human being who needed a friend.
If you listen to John's voice when he's talking about this, you can hear it cracking and him almost bursting into tears. He really is insecure about this. Makes you feel all the worse for laughing at Peacemaker's bullying earlier.
The response to this revelation by the Butterfly who was questioning him makes it all the worse. "Yeah. Humans are pathetic sometimes."
Even worse? The underlying certainty that John is a few ill-chosen words away from certain torture and death, and that if he was caught then the rest of the team wouldn't jeopardize the mission to save him even if they wanted to. The fact that he's the most useless and expendable member of the team standing there literally yards away from being sacrificed for the cause adds a certain poignancy to what could very well be his final words to them.
Unfortunately, killing Auggie did not automatically free Chris from his influence, and in fact may have delivered a significant hit to Chris's psyche, as Auggie's ghost winds up haunting him and gloating that he'll never get rid of him.
Peacemaker is clearly upset with the Justice League arriving late, as most of his friends are badly injured (especially Harcourt) and exhausted from the fight, and he had to make the hard choice of rejecting Goff’s offer without anyone to back him up.
Goff asking Peacemaker for help, during which there are flashbacks to significant moments in Peacemaker's life, draws attention to just how isolated Peacemaker's father made him. She also says "Thank you for feeding me." The season finale even shows Goff, in Butterfly form, sitting next to Peacemaker eating the last of her only food source.
The death of the cow is bittersweet; killing it might stop the Butterflies, but it's clearly just a blameless, dumb animal, and the Butterflies are understandably distraught at its death, with Butterfly Locke shedding a tear at its demise.
