The Boys has been putting its titular antiheroes through the wringer in Season 4. Butcher (Karl Urban) is being haunted by visions of his old CIA colleague Joe Kessler (Jeffrey Dean Morgan) and his wife Becca (Shantel VanSaten), driving him to take desperate measures in his mission to kill Homelander (Antony Starr) (or protect Ryan). Hughie (Jack Quaid) dealt with the death of his father (Simon Pegg) and was at the mercy of Tek Knight (Derek Wilson) in his dungeon. That’s not even getting into the past trauma that Kimiko (Karen Fukuhara), Frenchie (Tomer Capone) and Starlight (Erin Moriarty) have had to relive. It’s a good thing, then, that the Boys can still depend on Mother’s Milk (Laz Alonzo), who’s slowly becoming the MVP of Season 4.

MM took over leadership of The Boys after Season 3 and has led the group through some intense missions, one of which involved a farm full of superpowered animals. But these missions and family issues are starting to take a toll on MM, and The Boys isn’t shying away from showing it. In fact, the balance of personal and professional elements in MM’s storyline has been a major part of his character development, and it’s what makes him arguably the most important character on The Boys.

MM Has Always Been the Moral Bedrock in ‘The Boys’

Each of The Boys brings something different to the table; Butcher often uses blackmail or brute force to gain leverage, Frenchie’s skilled with chemical warfare, Hughie’s a quick thinker, and Kimiko is the muscle — quite literally — thanks to her Compound V-induced super strength and healing factor. MM brings something different to the table: he keeps The Boys on track by reminding them of their humanity. A great example comes in the Season 1 episode “Get Some,” when Hughie is still reeling after killing Translucent (Alex Hassell). MM has to remind him that the thrill of killing a Supe is just a rush, and can lead to a slippery slope. Another moment comes in Season 3, when MM chastises Butcher for using the Temp V serum to give himself superpowers and says “Butcher, the entire point of what we do is that no one should have that power.”

In fact, MM will often help others whenever he can. In the Season 1 episode “The Innocents,” MM tracks down the mind reader Mesmer (Haley Joel Osment) for help communicating with Kimiko. But instead of blackmailing him or threatening to hurt him, MM tells Mesmer that he’s set things up so that the psychic can visit his daughter. In a show that features superhero orgies and buckets of blood and gore, this human moment stands out. So does a moment in Season 2’s “Over the Hills With the Swords of a Thousand Men,” as MM sits with a shell-shocked Hughie in the guts of a beached whale. Even with The Seven bearing down on them, he risks everything to help Hughie, which makes him more heroic than the self-proclaimed “superheroes” Vought employs.

MM Tries To Take Care of His Own Family, With Varied Results

MM wasn’t always part of The Boys, as he left the group before the series started to be with his wife Monique (Frances Turner) and their daughter Janine (Liyou Abere). But his vigilante activities with The Boys put a strain on his family life; when the team lands in Vought’s crosshairs, Monique tells MM she doesn’t want to see him again. Though MM clears his name by the end of Season 2, he and Monique still remain separated. Further complicating matters is the fact that Monique has a new boyfriend, Todd (Matthew Gorman); Todd’s love for Homelander eventually leads to a confrontation with MM and MM decking him in front of Janine.

Season 3 takes time to explore MM’s backstory, specifically his hatred for Soldier Boy (Jensen Ackles). Soldier Boy threw a Mercedes-Benz through MM’s apartment when he was young, killing his grandfather and leaving him with obsessive-compulsive disorder. MM’s OCD had been shown before in the show, specifically his attention to cleanliness, but in Season 3 it’s given a new depth considering the events with his grandfather. It also draws a connection between him and Butcher; like MM, Butcher had his life upended by Homelander. “Soldier Boy’s like this steel sliver in my soul, and I gotta get him out,” MM tells Janine in a scene that’s achingly raw with emotion. The fact that Butcher and Hughie join forces with Soldier Boy only drives a wedge between them and MM — and the fallout has hit Season 4.

‘The Boys’ Season 4 Is Taking a Physical and Emotional Toll on MM

Even though MM’s now leading The Boys, it’s not an easy task. Most of the team has been consumed with their own personal problems, leading their operations to go south this season, and it’s physically taking its toll on him. But things got even more serious during this week’s episode, “Dirty Business.” When MM, Kimiko, and Starlight go to save Hughie from Tek Knight’s mansion, they wind up encountering Sister Sage (Susan Heyward), who starts to taunt MM about Janine. Throughout Season 4, Janine’s been showing signs of anger as she punched a boy, causing her to be expelled from school. Sage plays on this, telling MM, “You’ve cursed that girl,” leading MM to shoot her in the head and suffer a panic attack afterward. It seems as though MM will once again have to prioritize his family life over The Boys, a decision that carries more weight when you’re the leader of the team.

MM has had one success this season, and that’s convincing A-Train (Jessie T. Usher) to truly be a hero. The super-speedster is growing slowly disillusioned with Homelander pushing for superhuman supremacy and has helped The Boys out on several occasions. He even takes MM to a hospital, further evidence for his redemption arc. It’s a far cry from the flashy celebrity he was at the beginning of the series and a strong indicator of the strength of MM’s character, fundamentally impacting The Boys, both the series and the group, by providing a much-needed dose of humanity.

New episodes of The Boys premiere on Thursdays on Amazon Prime Video in the U.S.