Affably Evil: See his last interactions with Vas, Mother's Milk and Hughie.
All a Part of the Job: Besides wanting to take out The Homelander, this is the reason he joined, remained with and reformed The Boys. Billy loves nothing more than getting an opportunity to maim or murder a superhero.
Berserk Button: Superheroes, period. To the point where Billy was ready to assault Superduper because one of their members, The Klanker, accidentally called him a "fucking cunt" due to his Tourette's Syndrome.
And now he's got to the point where he's decided to commit superhero genocide. And killed off Mothers Milk, Frenchie and Female just in case they try to stop him.
Big Bad: With the deaths of the Homelander and Black Noir, Billy Butcher has become the main villain of the series.
Dark and Troubled Past: Like you wouldn't fucking believe. Abusive dad, fighting in the Falklands, losing his wife via rape-induced pregnancy and premature birth of a super-fetus... Butcher has a Dark And Troubled LIFE.
Empowered Badass Normal: He was a nightmare in combat to begin with - of the "brutalize and terrorize entire bars full of toughs into submission" level. A shot of Compound V simply enabled him to do the same to all but a handful of superhumans.
Fake American: Something he does in case he needs to fool someone, although he admits his Yank accent is crap.
Genocide from the Inside: His ultimate goal is to kill everyone who has been exposed to Compound V or has it in their system, despite the fact that it would mean killing all his closest friends and millions of non-supes as well.
He Who Fights Monsters: Played with; he admits this about himself in Butcher, Baker, Candlestickmaker. Billy was well on his way to being a violent sociopath until he met his wife Becky. Once she died, Mallory set him back on the fast-track to this by recruiting him into The Boys.
In the Blood: It's all but stated that Billy is a high-functioning psychotic, and that he inherited the trait from his father - the only difference being that Billy could be talked down by someone compassionate enough, while his father simply treated compassion as weakness. When intensely stressed, he literally dissociates from his actions and is incapable of controlling himself;
Butcher: ...that feelin' I get sometimes, whenever I really fuckin' go for it. ...Like I'm somewhere else, watchin' it happen.
Starlight: What about the guy, the one in charge? Hughie: He's in hell. Kickin' the fuck out o' the devil.
And since Hughie's not one for over-or-understatement, he's pretty much stating that he's 100% sure Butcher has already conquered Hell and is now very happily settled into his new job of torturing rapists and murderers for all eternity.
Manipulative Bastard: Played with. He will say or do anything it takes to to get the results he wants. When it comes to recruiting Wee Hughie he's no different, but he does seem to have genuine affection for him although that doesn't stop him from plotting to use Hughie as a soldier and a way into The Seven via Starlight.
Noble Bigot: Constantly mocks gay and transgender people, calls Americans "Septics" (Septic Tank = Yank) and (like many Brits) refers to Chinese food as "Chinky", but doesn't actually hate anyone other than supers ľ after all, he's happy to work with the Japanese Female and African-American Mother's Milk. Despite his sociopathic tendencies, he has an easy charm that allows him to get on well with almost anyone.
Poisonous Friend: When he begins to suspect Hughie of being a spy for The Seven after catching him with Annie outside the Flatiron, he immediately hatches a plan to keep Hughie out of the way by sending him to monitor Superduper after Malchemical joins their ranks.
Sleeping with the Boss: He's sleeping with Rayner, though it's not so much a relationship as it is vitriolic, self-imposed hatesex.
"When you're done we can go in and you can have your girl make me a nice cuppa tea. Proper tea, Monkey. Not that shit with a fuckin' tampon string in it you Septics think is tea."
— Billy Butcher, The Boys "The Name of The Game."
Tranquil Fury: Displays this when he goes off to murder Jack From Jupiter when he thinks Jack killed his dog Terror.
Woobie, Destroyer of Worlds: In Butcher's case, Played With. He wasn't exactly a nice guy early in his life. But he gradually became a better person when he met his wife, Becky. Then she got raped by Homelander, really Black Noir. And then she died when the child crawled out of her womb. He's implied to have Death Seeker tendencies, and in issue 65 after Black Noir and Homelander are dead, he admits, with tears in his eyes, that Becky would loathe what he has become.
Dating Catwoman: Has no idea that Annie is Starlight and a member of The Seven. For a while, anyway. He doesn't take it well when he finds out.
Family Relationship Switcheroo: It's heavily implied though never actually stated that Hughie's mentally handicapped "Auntie Mary" was actually his mother. Part of the implication is shared Butt Monkey characteristics; the last time Hughie saw the poor woman was after she released a seventeen-foot-long tapeworm into the toilet, an experience that not only left Hughie unable to speak for an entire year, but permanently put her in assisted care.
The Reliable One: Butcher specifically cites him as the guy holding the group together, he's the best investigator/detective of the group, and once Mallory was gone, the only sane one before Hughie was brought on.
Killed Off for Real: Although those two familiar bunches of floating balloons in the final scene hint that he and the Female may have survived.
Ooh, Me Accent's Slipping: At various points, he calls people "wanker" or "mum." This, coupled with his enrollment in the French Foreign Legion and his frequently inaccurate Gratuitous French, hints that he's actually a really crazy Brit.
Ax-Crazy: To the point where she goes into withdrawal if she hasn't hurt someone in a while. That said, she struggles against her nature every second of every day, and Frenchie tries to help her avoid hurting anyone.
Nice Character, Mean Actor: Possibly the shining example in the series. Homelander is an expert at putting up an appealing front to mask his psychotic and megalomaniacal tendencies.
Politically Incorrect Villain: After The Deep punches out the windshield on the plane they're trying to rescue on 9/11, he says: "Oh, fucking nigger! Fucking Nigger!"
Red Eyes, Take Warning: They mean he's trying very hard not to incinerate you with laser vision, or that you're toast.
Sanity Slippage: Heavily implied to be on the verge of a mental breakdown, as shown by his constant mood swings and the fact that he talks to his reflection in the mirror.
Shaggy Dog Story: He decides to become an amoral ▄bermensch because he thinks he has already killed and raped some innocent people, even though he has no memory of that happening. Turns out the reason he can't remember those things is that he didn't do them, it was Black Noir, his clone.
Smug Super: The root of all his self-aggrandizing, homicidal, and sociopathic behavior. Homelander likes to play "Hot or Cold" by reading the subject's body temperature and heart rate while taunting them about the things he's done to them or their loved ones.
The Sociopath: Ironically, he only becomes this because he believed he had committed the crimes that were actually done by Black Noir.
Woobie, Destroyer of Worlds: Ironically enough, may count as of issue 65. It turns out that he only got to this point because of atrocities he thought he committed, believing that he was far beyond saving. In truth, Black Noir, who turns out to be his clone, committed several of these crimes (including the baby eating) in an attempt to get Homelander to the point where he could perform his purpose: to kill Homelander.
The Alcoholic: The 9/11 disaster took a huge toll on her and seemed to loss all the passion she once had for her job, turning to drink as a result. Now she doesn't care at all about world affairs "as long as she's got enough gin inside her".
The Quiet One: Until his final big reveal, he only spoke in one instance, and that's when he was at Herogasm and shoved his thumb up Wee Hughie's ass, saying "Good soldier, good soldier" after catching him.
Let's Get Dangerous: Threatens Starlight when she refuses to accept her new makeover and origin.
The Reveal: He's a Homelander clone, and behind most of his atrocities, including raping Butcher's wife.
Worse: The fact that Homelander thought he was doing those deeds himself and couldn't remember it wrecked such havoc with his brain that he, as Butcher put it, basically turned into 'a complete fucking psychopath by accident.'
Oh, and the entire reason for his existence is that he's the only supe with the power to end The Homelander. Not being given permission to do so is what sent him completely insane.
Believing Their Own Lies: Appears to either be this or an extreme version of Kayfabe. When alone in the HQ of The Seven with A-Train, A-Train asks him a question and he begins answering with something that relates to the background of the Victory Comics character based on him.
Black Dude Dies First: Averted. He's actually the only member of the Seven (apart from Annie) to survive the series. At the end, he turns up (poorly disguised) in a new superhero group being formed by Vought American.
Enemy Mine: Suggests the Boys and the Seven do this after they're set up to wipe each other out. Everyone around him treats him like an idiot for it.
The Faceless: His face is almost always covered up by his old time diving helmet.
Flat Character: Has the least screen time and characterization of all The Seven. Probably Ennis commenting on Aquaman's (lack of) relevance in the grand scheme of things.
Screw This, I'm Outta Here!: Facing the impeding war with The Boys courtesy of the Homelander he left the The Seven's HQ, advising A-Train to take his copy of the Seven's merchandising contract and lay low.
Token Minority: "The least black black man on the planet" as described by Jack from Jupiter.
Reasonable Authority Figure: He never interacts with the team on panel, but he certainly comes off as cool, competent, courageous, consientious and principled, if ruthless and reactionary.
Screw the Rules, I Have Money!: His solution to the problem the real life US has with bombing/attacking Pakistan is solved by him bribing the Pakistani government into letting the US do whatever it wants.
Susan L. Rayner
Slap-Slap-Kiss: With Butcher. Except the "Kiss" part is vigorous hate-sex.
Nice Character, Mean Actor: Big time. Though "Mean Actor" is a bit of an understatement, considering when Swingwing was actually "mean" he pushed a young gay man off of a roof who had confessed his love to him.